Thanks for posting this! Just plugged in some dates in June, received:
We’re sorry. This property is not taking redemption bookings at this time. You can either book a cash reservation or search for another property.
Any way to know when points will be accepted?
Regarding it being adjacent to "Mel's Kitchen", this article in Eater San Francisco [dated Sept 2018] discusses the Mel's Diner transformation:
Mel’s Drive-In Transforms into Swanky Destination for Avocado Toast and $12 Cocktails
Rebranded as Mel’s Kitchen, the Van Ness location has a full bar and a new look
The 1950s kitsch is all gone. Classic diner Mel’s Drive-In on Van Ness closed earlier this year for renovations, and now it’s back as Mel’s Kitchen, a totally modernized and sleek and kind of sexy American restaurant with a full bar. The space now sports dark wood, burgundy booths, and soft lighting — the old-school fun and memorabilia have been scrubbed away.
The huge laminated menus with more than a dozen burgers are gone too. Now there’s one dry-aged, $16 burger and the Impossible Burger. You’ll find more bougie offerings, too, like ahi poke, acai smoothies, and avocado toast....
Edited to add:
This new Marriott had been the Opal, and based on the Opal's website, it seems the remodel was done prior to the Marriott take over.
Here's the Opal's website
And for those interested,
here's the Opal's Tripadvisor page