Mystic Theurge and Consumptive field

[flappeercraft]

So if someone with 2 or more casting classes such as a Mystic Theurge casts Consumptive field and due to it increases his CL, does it apply only to the class that casts it or to all?

[Inevitability]

All. There's nothing saying it only increases caster level for a single class, so one must assume that all of the character's caster levels are raised, even if they belong to different classes.

[Segev]

Counterargument: It says it increases your caster level, singular, and the spell is cast from a spell slot belonging to one and only one class. It probably only raises the CL of the class that spent the slot on it. I believe every other instance of a CL-boosting buff requires you to select the class to which it applies, unless it's a boost from a PrC that is deliberately advancing multiple at once.