Have you considered LanPass/LanChile ?
Your miles are accrued AA/BA/QF, etc
50Kmiles are enough to get access to OW lounges
Qantas are revamping their program... might be worth take a look...
But then... if you fly most AA, it's probably better (my opinion) to keep the AAdvantage... Miles just keep multiplying, that is a 10.000 mile journey appears in your statement as 30.000 (10K flown, 10K bonus, 10K AA flown).
Let me know what your final decision is