There's nothing stopping individual properties from offering their better guests Platinum or VIP benefits (which are the same, anyway, except a suite upgrade is guaranteed for the VIP with 7 days advance booking).

To give permanent (annual) Plat status to someone in this situation is another matter entirely. My view is it should be given only be given to those who earn it.

As for VIP: a one-time, five room, 20 night stay doesn't even come CLOSE to the criteria for invitation to ongoing VIP status. As I say, any property can offer the suite upgrade if they so choose. And many often do.

Cheers,