Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.1030 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
If you want your US status perks on your AA flight, then you should replace your AAdvantage number with your Dividend Miles number in your AA PNR.
It sounds like your AA flight is not an "award" flight, but merely a cash flight paid for with Amex points.