Originally Posted by
SFOSpiff
That's not entirely true. Continental has a marketing relationship with Virgin Atlantic (which is not in *A); flying VS earns you both miles and EQM with CO.
Similarly, UA has an agreement with Aer Lingus that earns miles but no EQM.
Both UA and CO have agreements with Hawaiian Airlines that earn you miles on inter-island flights.
And so on...
But I think you still need to be careful about which FF number you input into your reservation record. Somebody please correct me if I am wrong, but it is my undertsanding that if you fly Aer Lingus Express on a UA code-share, you wil not get credit if you use your CO OnePass account number, but you will get credit if you use your UA MileagePlus number.