Only two - both on Bora Bora!
I can't believe the replies I'm reading in this thread.
The OP did not want to know about funky W hotels or about properties which are generous with upgrades.
The question, quite specifically, was which hotels can be compared with the extreme luxury of Peninsula or Four Seasons hotels.
I only know of two in the entire chain - the Bora Bora Nui and the St Regis Bora Bora. They have luxury rooms and attentive, personalised service, right down to the yacht or speedboat from the airport to the hotel.
W Hotels are out for a start, as they are too narrow in their appeal, and much as I like the Westin Melbourne, which one poster cited, it is an excellent five star hotel but has no lounge, no VIP gifts and no personalised service.
I do like the St Regis Monarch Beach, but it has lost its butler floor and is far too impersonalised to be compared to a Peninsula.