A) You generally don't know if something's a rewards card when they're using it (especially over the internet).
B) Do you want to be told - "sorry, I can't accept your BoA airline rewards miles VISA card, please use a different VISA card"? I'm pretty sure Visa/MC TOS prevent that.
B) Do you want to be told - "sorry, I can't accept your BoA airline rewards miles VISA card, please use a different VISA card"? I'm pretty sure Visa/MC TOS prevent that.