Would also like to know this, and not to derail, but if at the same time someone could confirm that Spell Casting Fury does indeed affect bard chants and/or bellows, that would be fantastic.
They appear to affect my Bard songs. I'd recommend getting them. If they don't affect the Dot's the will affect the DD's that use mana. In fact, I argue that Bards can take advantage of most of their AAs, up to about 558, if I recall.