nope doesn't matter,the experience gained by your growth pet would be separate from the experience you gain...so as long as your wolf is summoned, then whenever you kill mobs you get separate experience points. and what your pet gets would depend on the level of the mob killed, his level and your level...well other SRO vets can correct me if imma wrong...
btw, since i am a wiz i die a lotsa times, so my char level and wolf level are the same, i envy my wolf since even when it dies it does not lose xp...
