I believe they come from the same bucket as QF awards. As a QF WP, I get award seats on AA from X and T inventory, so I would expect it to work the other way around.
Economy awards on domestic Australian flights are readily available, especially for Gold and Plat QF members, so I expect that will also be the case for AA Plat and Exec Plat members. Business Class awards can be harder to find, but are still there so long as you are willing to fly off-peak times of the day and avoid high demand times like school holidays, long weekends etc.
But, a high status QF members can request an award seat be made available when one does not exist on QF flights (this is unpubished and the request is at the discretion of the Premium Desk and considered by the revenue management dept - no guarantees). But an AA member does not have the abality to make such a request.
Also note that a QF FF member can use points for upgrades. And for international flights can waitlist for an upgrade. Now we all know that the points required for these uprades and QF awards are about to go through the roof (come May 2005). So that makes AAdvantage even more attractive for award flights in Australia/NZ.