Still waiting for my 1500 United.com booking bonus from July as well. They first said it would be up to 8 weeks for the credit. I wrote them again since the 8 weeks has now passed. I received this today:
"In order to provide a thorough and complete response, your inquiry will require some research. If our research indicates that an adjustment needs to be made to your account, it will be made within four weeks."
- Tom