I would suggest that you sign up for AA's frequent flyer scheme

You are likely to get much better value from it.

Assuming you are doing LHR-DXB-SYD-AKL the distance is about 12,246 each way

The Y class journey will earn 12,246 and the M will earn 6,123 miles for a total of 18,369 miles. This is less than would be accrued to QFF but will have a much higher value for redenptions. e.g. a business oneway UK-NZ costs 60,000 AA points vs 130,000 Qantas points plus the Qantas redemption will have several hundred pounds cash surcharge to pay too

For attaining status with AA, getting gold status requires that you earn 25,000 qualifying points or miles in a calendar year - this trip will earn approx 24,492 of them

AA has a fast track to Platinum status ( which is equivalentish to Qantas Gold ) and gives lounge access. If you sign up to it before the journey ( costs USD250 iirc ) , you will attain Platinum status on the outbound journey and have lounge access on the jouney back plus earn an additional 6,123 miles as a platinum bonus giving 24,492 miles

AA Platinum status would be of value if you use One World flights in Europe and has similar benefits in OW as Star Gold has in Star Alliance