Consumptive Field's effect on Caster Levels for a multiclass character

[Lawful Good Garagos]

Consumptive Field is a level 4 Divine Spell. It kills any nearby creature with negative hit points that fails a saving throw. For each creature killed, your caster level increases by 1, to a maximum bonus of half your caster level.

So if a Cleric/Wizard casts Consumptive Field once, would the Caster Level bonus apply only to his Cleric Caster Level, or to both his Cleric and Wizard Caster Level?
Since he is casting Consumptive Field as a Cleric, initially I thought that only his Cleric Caster Level receives this bonus. But if we interpret this situation by RAW, should both the Cleric and Wizard Caster Level receive the bonus?

If the first Consumptive Field only boosts the Cleric Caster Level...
could the character cast Limited Wish, which he prepared as a Wizard, to cast Consumptive Field a second time, and therefore gain the bonus to his Wizard Caster Level as well?

To take a full example that includes feats and items

if a Cleric 15/Wizard 13 with
-Bead of Karma (+4 caster level)
-Practiced Spellcaster: Cleric (+4 caster level when casting as a Cleric)
-Orange Ioun Stone (+1 level)

Current Cleric Caster Level: 24 = 15 class + 4 karma + 4 feat + 1 stone
Current Wizard Caster Level 18 = 13 class + 4 karma + 1 stone

So if the character casts Consumptive Field which he prepared as a Cleric, his maximum Cleric Caster Level would be 36?
If Consumptive Field can give a Caster Level Bonus to Wizard Caster Levels, the maximum CL of the Wizard would be 27?

I'm curious about all these Caster Level abilities because I heard there was a feat called Theurgic Specialist in a Dragon magazine, that allowed you to add the Caster Levels of all your arcane and divine classes, for spells belonging to the Wizard's specialization school.

So in the example above, if everything is in accordance with RAW, the Cleric 15/Wizard 13 would have a caster level of 63. So if his Wizard specialization school is illusion, he can cast a pretty mean simulacrum . It would be akin to using mortal means to gain power rivaling the gods.

 

[Patryn of Elvenshae]

Unless it specifies, the bonuses apply to all your caster levels; just like, say, the Ioun stone that does the +1 to CL thing.

 

[RUMBLETiGER]

Your example has a level 28 character. At that level of Epicness, this character can do whatever the heck he wants.