Details here:
https://www.aa.com/i18n/aadvantage-p...nt-rewards.jsp
buried way down at the bottom of the T&C:
Miles back rebate
- All mileage redemptions will be tracked starting the day this reward is chosen through the following 365 days
- When you’ve redeemed your total miles for the chosen reward or at the end of your 12-month period, you’ll get a lump sum deposit of bonus miles credited back into your account equal to your total redemptions, up to the total miles amount for your chosen reward
- Allow up to 72 hours after your 365th day for miles to be deposited into your account. If you do not receive your miles, please contact us.
- The mileage redemptions must be completed from the selecting member’s account
- Travel for flight, hotel and car redemptions must be completed before the 365-day period ends
- Redemptions completed prior to selecting this reward are not eligible
- AAdvantageŽ bonus miles awarded through this offer don’t count toward AAdvantageŽ status qualification or your Million Miler™ balance
- AAdvantageŽ bonus miles awarded through this offer are subject to expiration according to the general AAdvantageŽ program terms and conditions