Parsing the language of the statement most definitely says what Hyp says that it says. Of course, ever since 3.0, the glossary has been a poor place to look for rule answers.
Perhaps the question we should all be asking is "why do you need to know the type of the ability?" There are several possibilities:
1) For Dispel Magic purposes. IF this is what the qustion is about, then it doesn't matter what type of ablilities an item's bonuses are. You can still target the item per the description of Dispel Magic, threby suppressing it. However, the ablity granted is not a creature, spell effect, or item, and o it cannot be targetted. Thus you have to pick an item on your foe and hope that you get the right one.
2) Shapechange. When you shapechange, you lose your Su abilities. However, an enhancement bonus from an item isn't your ability. If the form you take can wear the item, then the item will impart that ability onto you still. If it can't wear it, you won't get it.
3) Something else?