Sublime maneuvers do not have any weapon requirements
Page 38 of Tome of Battle has the full and complete rules for what is required for initiating a maneuver. We see some requirements:
“you must be able to move.”
“A maneuver might require an immediate, swift, move, standard, or full-round action”
“a maneuver that is currently readied and unexpended”
- “if you are a crusader, the maneuver […] must be granted to you”
Nowhere do we see anything about a weapon.¹ And when Tome of Battle introduces the disciplines, it has this to say about the associated weapons:
In addition, various weapons lend themselves to the philosophy or maneuvers of different disciplines.
(Tome of Battle pg. 41)
That these weapons “lend themselves to the philosophy or maneuvers of” the disciplines is a long way away from stating that these weapons are required.
For my last piece of evidence, the master of nine prestige class is all about mastering all nine disciplines. The example character for this prestige class is armed only with a +2 greatsword, even though his readied maneuvers are from Desert Wind, Shadow Hand, Stone Dragon, and Tiger Claw (he also knows maneuvers from Diamond Mind, Iron Heart, and Setting Sun, though he does not have these readied). The greatsword is only associated with Stone Dragon.
Associated weapons are not just flavor, however
While maneuvers themselves don’t require a discipline’s associated weapon, several feats do.
First is Blade Meditation, which is Tome of Battle’s equivalent of Spell Focus. Among other benefits, it grants “a +1 damage bonus with all the preferred weapons of your chosen discipline when using a strike combat maneuver,” so that part of it requires the weapon. (The other parts, the +2 bonus to the chosen discipline’s associated skill, and the +1 bonus to save DCs for the discipline’s maneuvers, do not require the weapon.) Notably, Blade Meditation lists the associated weapons for each maneuver here—because outside of this and a few other feats, those weapons aren’t really used for anything and you might need a reminder.
Then there are two related cycles of feats, a general feat for each discipline that serves as a requirement for a tactical feat with that discipline. While many of these don’t care what weapon you’re using, several do:
Desert Wind Dodge grants (in certain circumstances) +1 fire damage to any attack made with “a scimitar, light mace, light pick, spear, or falchion,” which is the list of weapons associated with Desert Wind.
Shadow Blade is the Shadow Hand general feat, and adds your Dexterity bonus to your damage “with one of the discipline’s preferred weapons.”
Reaping Talons is Tiger Claw’s tactical feat, and requires the use of “preferred weapons of the Tiger Claw discipline” for each of its three tactical maneuvers.
Shards of Granite is Stone Dragon’s tactical feat, and requires “using one of the preferred weapons of the Stone Dragon discipline (greatsword, greataxe, heavy mace, or unarmed strike)” for each of its three tactical maneuvers (and yes, it repeats the list of weapons each time).
Finally, the bloodclaw master, a prestige class specializing in the use of the Tiger Claw discipline, has a feature that gives special benefits when using Tiger Claw weapons.
Maneuvers (and feats) do what they say they do
The supernatural flames of the Desert Wind discipline don’t damage your weapon, because they don’t say they do. Likewise for other disciplines (and the Desert Wind Dodge feat). Setting any weapon on fire would damage it; the unarmed strike is not unique in this regard (though obviously the damage will be uniquely notable).
For the sake of backing up the negative and proving that the 3-4 points I’ve extracted are the sum total of requirements, the full rules text is below:
Initiating Maneuvers and Stances
To initiate a maneuver or a stance, you must be able to move.
You do not need to be able to speak. You initiate a maneuver
by taking the specified initiation action. A maneuver might
require an immediate, swift, move, standard, or full-round
action to initiate. The process of initiating a maneuver is
similar to that of casting a spell or manifesting a psionic
power, although there are some key differences (see
below). You can only choose to initiate a maneuver that
is currently readied and unexpended. In addition, if you
are a crusader, the maneuver you choose must be granted
to you—you can’t choose to initiate a maneuver that is
currently withheld.
You initiate a stance as a swift action. A stance remains in
effect indefinitely and is not expended. You enjoy the benefit
your stance confers until you change to another stance you
know as a swift action. You can remain in a stance outside
of combat situations, and you can enjoy its benefit while
exploring or traveling.
(Tome of Battle pg. 38)