[Davros]

Actually acid bomb is the one you should be able to learn, not Firebomb. Both are 4th level alchemy spells - wizrdry therefore doesn;t come into the equation. Your requirements for these spells should be :
Level 8 (pure caster) - I presume that jezebel has always been a bishop (ie not a converted mage or anything - that could be your issue - need to be seen as a level 8 in all spell schools - you can carry over and keep increasing your wizardry skills when converting a mage, but all ather start at level 1).
45 in casting school - with the 10% allowance you should have a 46 skill in water, and a 43 skill in fire.

Hope this helps.