If you type "mega bonus" into the search box for the MR forum, you'll find many of the reported bonuses. It appears to vary by member and their stay patterns and status. Generally, so many bonus points for so many stays IIRC.

Only way I know to get anything beyond what Chris mentioned (my wife did the VISA promo and got bonus points and silver) is to challenge, based on your status with another accommodation provider. There is further info on that in the archives.

MR appears to be pretty strict on status levels and how to get them.

Pat