Spell-like abilities are not spells. They have their own rules under a separate section (Special Abilities, rather than Magic, which covers spells). Key to point, the description for spell-like abilities reads thusly:
Spell-Like Abilities (Sp): Spell-like abilities, as the name implies, are magical abilities that are very much like spells. Spell-like abilities are subject to spell resistance and dispel magic. They do not function in areas where magic is suppressed or negated (such as an antimagic field). Spell-like abilities can be dispelled but they cannot be counterspelled or used to counterspell.
The key point in that is the very first sentence, they are "very much like spells". That strongly implies that they are not spells, although it doesn't outright state it.
Secondly, there are sections of the book that explicitly state both Spell and spell-like ability in the same sentence. Enough times for me to believe that this is deliberate, and that unless spell-like ability is explicitly mentioned, they are not affected. Simply stating spells is not enough.
Some examples that I have found to support this are:
Spells, spell-like abilities, and energy attacks (even nonmagical fire) ignore damage reduction.
Disruptive Spell (Metamagic):
Your magical energies cling to enemies, interfering with their spellcasting.
Benefit: Targets affected by a disruptive spell must make concentration checks when using spells or spell-like abilities (DC equals the save DC of the disruptive spell plus the level of the spell being cast) for 1 round. Targets that avoid the spell's effects avoid this feat's effect as well. A disruptive spell uses up a spell slot one level higher than the spell's actual level.
A summoned monster cannot summon or otherwise conjure another creature, nor can it use any teleportation or planar travel abilities. Creatures cannot be summoned into an environment that cannot support them. Creatures summoned using this spell cannot use spells or spell-like abilities that duplicate spells with expensive material components (such as wish).
Clay Golem Immunity to Magic (Ex):
A clay golem is immune to any spell or spell-like ability that allows spell resistance...
These examples are taken across as many different areas as I could find. The core rules, feats, spells and special abilities. There are more examples available for each of these areas, however I have included only one of each. A google brings up a large list.
This cannot simply be coincidence or an accident. It is clearly by design, meaning spell-like abilities and spells are two different things. Unless spell-like abilities is explicitly mentioned, then they are not affected.
One argument against this point that keeps being brought up is the fact that dispel magic ignores the pattern above, that it only mentions spells. However it is key to note that in the glossary, under the rules for spell-like abilities, dispel magic, along with antimagic field, is explicitly mentioned. Therefore we still maintain the patter above, where spell-like abilities only apply when explicitly mentioned in the rules.