Re-read the T&C. Looks like 20x for all local and overseas spend, online or off - outside the designated 20x categories (dining, airlines, travel agency and medical). Normal exceptions apply ie AAVS, electronic wallet, etc.
Unfortunately dgittings, I believe the required 20K annual spend is for each card that plays this promo (CUP and VISA, principal and supplementary). That said, the spend for this promo will be counted towards the 20K. So it should not be too difficult to meet.