| Simon Legrande |
Caster level bonuses affect the level-based numerical parts of a spell. A first level character with +2 CL doesn't get the spell list of a third level character, their spells are just calculated as if they were third. For example, the character casting magic missile would get two bolts instead of one and have a range of 130' instead of 110' but he won't be able to cast acid arrow.
Edit: They would also apply the +2 bonus to caster level checks like overcoming spell resistance.