Suppose that I want to have a first-level wizard school ability, and that I took an arcane bond with a weapon. Say that for whatever reasons, I take the rest of my levels in a different casting class. Can I still magically enhance my Arcane Bond weapon without taking the Craft Magic Arms and Armor feat? Arcane Bond says:
A wizard can add additional magic abilities to his bonded object as if he has the required Item Creation Feats and if he meets the level prerequisites of the feat. For example, a wizard with a bonded dagger must be at least 5th level to add magic abilities to the dagger (see Craft Magic Arms and Armor feat).
Now, usually a wizard would do this by reaching CL5 as a wizard, but the Craft Magic Arms and Armor feat only specifies you have to be CL5 to use it. Certainly you can always magically enhance a weapon with the feat, then re-bond to it, but that's not the question. If I am a wizard 1 / witch 5 (for example), am I able to magically enhance my arcane bonded weapon, e.g. to be a +1 weapon without having the Craft Magic Arms and Armor feat? If not, why not?
Note: This is not specific to the wizard/witch combo, I'm asking about all caster combos with wizard in general.