You don't necessarily need to report the post individually. You could indicate a comment saying "Please check the user's post history, where he mostly spam in bounty threads.". From there, you'll be saving a lot of time and your report won't be repeated on the moderator's end making both your job easier and without you worrying the report limitation.
I think I tried it several times, but it was not successful because only the post that was reported was deleted. Although there is no doubt that it would be much easier on the part of the person doing the report, but the moderator still has to manually delete each post using the user post history - which may not be the easiest way from their perspective.