No mention of any restrictions to certain types of spending for the bonus on my offer:
Start using your British Airways Visa SignatureŽ Card to earn your bonus miles.
Offer valid from 4/15/2011 to 6/30/2011
Now your purchases can get you closer to your next destination.
for a limited time earn 50% more BA miles in addition to your regular earnings of:
2.5 BA miles per dollar spent on British Airways flights
1.25 BA miles per dollar spent on all other purchases
Earn up to 20,000 bonus BA miles during this promotional period