First, some quotes:
In the D&D faq:
A feat sometimes requires you to have a certain ability score, which
is the case with Two-Weapon Fighting (it requires Dex 15). A character
has, say, Dex 13, but wears an item, in this case gloves of Dexterity
+2, and now her Dex score is 15. Can she take the feat and have it be active only when she wears the item?
Actually yes, she could take the
feat, but she would lose the use of the feat if, for whatever reason,
she loses the bonus from the item.
From the metabreat description:
Dragons (and other creatures) have developed ways to control their
breath weapons to produce varying degrees of effects, from the subtle
to the conspicuous. To take a metabreath feat, a creature must have a
breath weapon whose time between breaths is expressed in rounds.
Therefore, a hell hound (which can breathe once every 2d4 rounds) can
take metabreath feats, whereas a behir (breath
weapon usable 1/minute) cannot.
And old quote from the wizard's forums, the link used to be this, but is it no longer accesible.
Vestige granted feats and abilities weren’t intended to qualify one
for prestige classes or other feats
From these excerpts, we can get than:
Magic Items satisfy ability score reqirements for feats, even if they
are not permanent part of the character. Of course the feat is
rendered unusable is the stat boost is lost. If this applies to abilities that the character has not in a permanent basis, I have found nothing.
Breath weapon Abilities granted by Vestiges would qualify for the
metabreath feats, as they work as breath weapons (as noted here)
and have a recharge time measured in rounds. Some DM would rule
against this, however, because the text "breath weapon" does not
appear anywhere on the text of the ability.
The quote from wizards forum says no, but is nowhere to be found
except in other quotes.
- Many classes and feats have a prerequisite "being able to cast X
spell". A wizard that has the spell in its spellbook qualify, even if
he has not the spell prepared, because he could prepare it while learning the feat. It is
reasonable that this could be applied to binders, as they can choose to
bind the adequate vestige while learning the feat.
I would say this is entirely DM call. No direct answer from official, and while there is enough tangencial support in favor of allowing metabreath feats for binders, there also some reasons that could be argued against that.
The following in my personal opinion:
Binder is not exactly a overpowered class, although it can be considered a versatile one, the metabreath feats haw their own cons (they increase the recharge time for the breath), and most of the reason against ruling this way come from the non-existence of rules that explicitly allow for it, rather in the existence of rules explicitly forbidding it, so I would allow taking the feat.
Noted that the Faqs and custserv are not considered as RAW, so I edited the post to reflect it. However, these quotes are the most close aproximation to it that I could find, and seems that there is not oficial clear source that can be considered RAW and that specifically address this question, so I will leave the rest of the answer as it is.