A quick update regarding my points and the promotion - my points/miles posted as the AY flight number, so ineligible for the promotion. However, just had a quick chat with the EC Gold line and the lady there said she would put a request through for the AY flight to be deleted from my account and replaced with the equivalent BA flight no, although "it may take 10-15 days". So in theory this should then maintain my eligibility for the ongoing promotion. I'll see what happens!