Thank you all for your responses re Platinum benefits being possibly applicable to all those in one booking (2 rooms including Platinum member).
I did indeed email the Sofitel and I am happy to report that I got a positive response!
I was interested to hear about My Resorts and you are absolutely right ququin.
"Share your Platinum resort privileges with family and friends - Exclusive to Platinum members"
...and Sofitel Bali is on the List!