I had a problem with this at the Sofitel Moorea, as I have not yet received a physical card. The IT system did not recognize my status and as a result the person checking me in insisted that I was not Platinum. In the end, I had to log into my account online to show her and then suddenly the General Manager appeared, apologized for not knowing a Platinum member was arriving, and I was offered an upgrade to an overwater bungalow for the first night, and then to move to a beachfront bungalow for the remaining three nights (no overwater bungalows were available over sold out New Year's Eve). I had booked the only available room type (which happened to be the cheapest garden view).

So this worked out quite well for me, thanks to the advice on this thread! ^