In LEED 2009 there are 100 possible base points plus an additional 6 points for Innovation in Design and 4 points for Regional Priority. Buildings can qualify for four levels of certification:
Certified - 40 - 49 points
Silver - 50 - 59 points
Gold - 60 - 79 points
Platinum - 80 points and above
In searching the Internet a bit, I didn't come across the "Platinum Plus" certification, so it's possible that someone is trying to say they're aiming for the very top of the Platinum certification, e.g. 98, 99, 100.
It sounds like "6-star hotel" to me, when the generally agreed-on international peak is "5-star," but this is just an opinion.