I used to work for the RSPCA and left in disgust due to whole manner of issues including the welfare of some of the animals in its care!!
However, if they publicise this well and reward the supermarkets who take animal welfare seriously which in turn will hopefully encourgage other supermarkets to do the same then it can't all be bad.
Yes the RSPCA have messed up in many areas - over stretching themselves, not following up their Freedom Food scheme, acting as prosecuter too often instead of educator and helper. Taking 2 minutes of your time to vote for an award that may help to promote animal welfare is not endorsing the RSPCA as a whole, but just this award.