I'd recommend giving your rear upper and lower control arms (and mounting locations) a serious look over. If you would have thought it is coming from the front, (which makes more sense as you feel it in the steering wheel), make sure your power steering rack isn't leaking or low on fluid, not that a bearing race was pushed in from the jar of landing your aerial stunt. Also make sure your steering isn't sloppy when the vehicle is off, you'd be able to tell if there is inherent play in the system.
Is there a specific reason you caught air the other day? Let me guess, you saw your good ol' bud Kyle doing double B's off a gnarly berm on his 'Laris and he bet you a beer to give 'er a go?