I didn't see this in the changelog for 1.4, but:
When I force AI surrender, and they agree, I get their soverign. Any spells on the soverign (ie tutelage) are kept, but do not fall into my enchantments list (and thus I do not pay upkeep for it). In addition, I cannot dispell those enchantments (not that I would want to, since I have them for free / they are beneficial).
