You have to decide from here on in, which airline alliance you would like to stick with and earn your miles there.

MPC is one of the hardest to get elite levels (ie their GOLD level, Oneworld Sapphire effectively requires you to fly 90K in a year if you have no status with them) Whereas if banked on AA's programme, you'd only need 100K to earn Exec Platinum status, their highest level in Oneworld Emerald.

Alternatively you may opt for AA's Platinum Challenge where you may earn mid level Platinum status by short cuts. You'd only need to fly about 20K miles to get to that level instead of the required 50K. But still you need to FLY to get that. More information may be found on AA's forum. Do a search under "Platinum Challenge".