Since an awesome blow combat maneuver is separate from a bull rush combat maneuver, it does not benefit from the bonuses provided by Improved Bull Rush (prerequisite) or Greater Bull Rush. Nor, it would seem, does an awesome blow combat maneuver benefit from any racial or trait bonuses to a bull rush. But it is a combat maneuver, so shouldn't it have 'Improved' and 'Greater' feats associated with it? I've tried my hand at searching, but is there such a thing as Improved Awesome Blow or Greater Awesome Blow?
And Awesome Blow is, pardon the pun, already pretty darned awesome as is. Bloody impressive feat both mechanically and thematically.
The real question with Awesome Blow is: can you smoke someone up into the air, AoO them as they fall back into your reach, and then Vicious Stomp them as the crumple at your feet? That would be classic physical comedy...