Answering my own question above: there is now a lounge at the Sheraton, therefore Plats can no longer use the lounge at the San Cristobal.
However, during my last stay they were having problems with the aircon on that floor, so the lounge was closed and Plats were being directed to the San Cristobal. Therefore I wasn't able to check out the offering. I'm due back in September, but if anyone can elaborate on the offering, etc I would be happy to hear!