I guess there's some but I don't think that ranking would be helpful, I don't know what criteria they will use in making a ranking and I think a ranking does not give any assurance to the bounty hunter's success. Honestly, most of what I can see are just a list of bounty available, that combined from bounty here in the forum and outside the forum, but I'm not interested in joining bounty that has no announcement in the forum as members in this forum are more interactive.