It's probably very property specific list.
If you stay at the same property for a sizeable number of nights, they recognize you and they treat you better. Usually, this involves upgrading you during subsequent visits, giving you small perks like free drink vouchers, accomodating any of your special requests etc.

Other than that, there is no such list called VIP list SPG wide. If you are a platinum, officially you are only a platinum, nothing more, nothing less.
Beyond that, if you are able to stay more than 75 nights and more than 100 nights, benefits vary. These benefits can be found on spg website.