I have started doing the same thing. I go through eShopping to buy SuperCerts on GC.com, redeem them for AA Gift Cards, and then use those to ticket reservations. Works brilliantly (and I get 3.25 miles per dollar spent on tickets with SPG Amex, vs. only 2 when using CitiBusiness to buy directly from AA).

But another potential problem is that by not buying the ticket with a CC in your name, with the same billing address as your AAdvantage account, you might run the risk of SSSSpecial treatment (because the system might consider Gift Cards to be like cash). Does anyone know?