Interesting discussion here.

There's no question that Qantas Frequent Flyer is one of the world's worst programs for redemptions and upgrades, AA is heaps better. Examples: a biz class award SYD-PER is 17,500 AA miles but 36,000 QF miles for the exact same QF seat. For an award SYD-LAX in F, yes there's an occasional seat available, it's 144,000 QF miles but the same seat is 72,500 AA miles.

As for (international) upgrades, QF really only do op-ups - a sort of lottery on the day. Whereas AA on their own metal will confirm an upgrade in advance, and high-status pax get 8 systemwide upgrade vouchers a year. [And similarly UA and AC.]

Looking at upgrading a QF flight with QFF points and trying to credit the miles to AA, you actually can't credit normal Qantas economy fares to AA. Regular Qantas economy flights earn zero when credited to AA (and AA returns the compliment.) You could pay more (approximately double) to get into a higher economy class, and then get the GA to change the earning-FF-number and maybe earn some AA miles that way, but you would probably be better off just buying AA miles outright.

The other problem is there's no creditcard offering AA miles in Australia, doubtless due to Qantas' influence with the financial institutions.

So the interesting part is how to earn AA miles indirectly by getting a 'general' Amex or Diners card and crediting to SPG (Starwood/Sheraton) then transferring the miles.

There's a catch, unless you have high status with Sheraton/Starwood you can't transfer small amounts of miles. And you have to move 20,000 to get the 5,000 bonus to make it worthwhile.

So if you have exactly 60,003 Amex membership reward points you can move these into 20,000 SPG points and then convert these into 25,000 AA miles giving an exchange rate of 60,000 Amex => 25,000 AA, ONLY IF you have at least 60,000 with Amex.

Of course if you stay at a few Sheraton hotels you can earn some SPG points that way, and as Dave mentioned you could just buy the 20,000 SPG points outright and move them into AA, useful after you've bought your annual quota of AA miles at a sale.

In your position I'd be looking closely at the benefits of the AC and UA programs, confirmed upgrades, realistic redemption-costs, lie-flat seats etc - forget about Qantas for international travel and just keep earning a few QF points on a CC for domestic upgrades.