Actually those are the level caps for vanilla SoA, if you have ToB installed you can earn up to 8 million XP which translates to the following max lvls:
Wizards & Druids: 31
Rangers& Paladins: 34
If you're a F/M/T exp. is evenly divided over the three classes so that would make a 18/17/22 F/M/T, so no that means no lvl 9 spells unfortunately..
And like Tallima says it's always a good idea to have the tables section of the manual handy while playing.