Officially it's 2 pieces at 6kgs each, however, if one is up to 9kgs and the other is a small bag that does not push it over the total weight limit, then it will be allowed. Cardholders do not get additional allowance as it is based on cabin travelled and not on card status. In recent days BAA and BA have been asking passengers to carry as little as possible so as to make getting through security as fast and painless as possible.