If you have the AA Visa, on the statement where the AA purchase shows up (once that statement closes).

If you have the AA Amex, and your valid AA purchase posted as "AA AIR" instead of "AMERICAN AIRLINES", then the $150 credit may not show up for many months later, and only after endless followup phone calls. (Of course, that issue may have since been cleared up, but it certainly affected a number of us a few months back.)

Thanks for the info, yeah mine says
" AA AIR T0013*****2 DALLAS" and I'm using the AMEX AA card. Ill wait till the months statement closes and see what happens.. Hopefully it does, if not calls or secured mails!

data point:
so my statement closed yesterday and the $150 appeared! No calls or emails needed on my part!
FYI: have the AA amex.
Purchase came up as: "AA AIR T00******** DALLAS"
Then statement credit showed up on the last day of cycle as: "Congrats! Merchant Spend Bonus -$150.00"

:)

So, is it still ok to buy $150 in gift cards for the credit? Anybody had any issues lately? I applied for the offer with $150 credit on AA within 12 months of opening.

I'm really glad I bought a beer on my last AA flight with my AA Amex.

Check your statement to verify if you get the credit. I used AA Visa (personal and business) for in-flight purchases (this was back in May 2013) and it didn't post the statement credit. I eventually got a $50 gift card from aa.com

The credit appeared on my account, and I had no idea why it was there. I googled for it and wound up on this thread. A nice surprise.