[Taqwus]

Yep. Self-buffs cast by a communion master will affect the slaves. This is particularly spiffy for Earthpower, since that 4 reinvigoration synergizes well with fatigue spreading.

By the way, you have to be really, REALLY careful if a communion master ever casts 'Phoenix Pyre'. Done as part of a plan, the results can be interesting. Done unintentionally, and, well, they can be hilarious.