@mixedmath Probably that depends on how many people offering bounty and how many potential bounty solvers are aware of the room.

Perhaps some people know about this from the post on meta. I also occasionally mention it in chat.

And I have also left comments to few people who offered bounties without getting any answer. (Like I did to you. I hope that is not too "spammy".)

Occasionally the room might appear in the sidebar. And people can see it in the list of rooms associated with this site.

Other than that, I cannot think of other possibilities how to promote this room

(I am not sure whether the discussions about this room should be held here or elsewhere. Originally I thought that the traffic in this room would consist mainly of the links to questions. But I was probably too optimistic.)