As far as I know Etihad is only mileage earning partner with AA. In theory you can earn award flight on Gulf with AA miles. The reason I said in theory is because Gulf is not one world partner so AA has to submit in writing a request and reply comes in 5 days. I have tried multiple times this option but was never successful. In fact one AA rep told me that in his carrier of 3 years he has never seen any request ever successful which was pretty disappointing. So once again in theory this is definitely a possibility.