From Fedrooms website: "Find links to participating hotel loyalty programs for your favorite brand. Don’t forget, travelers are eligible to accrue points when booking the FedRoomsŪ Rate." https://www.fedrooms.com/traveler.html

You can book the Fedrooms rate either directly at the Fedrooms website or at the hotels' website by using the promo code for Fedrooms.

The ideas floated or hinted at upthread that there is something wrong with federal traveler's receiving and keeping points/miles obtained (on the same basis as any other traveler) during the course of official travel or that a federal traveler may not use his/her own points to upgrade the traveler's room or that there is some contract between Fedrooms or GSA and hotel chains precluding miles/points on Fedroom or government rates is ludicrous and contrary to federal law which explicitly gives federal travelers the right to receive and keep miles/points from official travel for their own use. Obviously, bribing federal travel officials and/or conference arrangers to contract with a particular chain or property for conferences or the like, whether by cash, points, or upgrades to the federal travel official or conference arranger, does not fall within the above section of federal law and would likely be illegal. Whether federal travel officials and travel arrangers could keep bonus points/stay credits for contracting for conferences, which are available on the same basis to anybody arranging a conference, might present some issues.

When I was traveling as a fed, I frequently checked fedrooms to see what the local landscape looked like. If memory serves me, I don't remember seeing at that time even one single Marriott property listed. Lots of Hilton; no Marriott. Likely, at that time, there was some type of Marriott policy precluding fedrooms listing. Don't know if that's true today.