I think bounties are open to everyone and the minimum rank of jr.member is fair because not all bounty hunters work well and sometimes they even do or spread FUD on the project.
Yes, it still looks very fair to this day, depending on which side one will judge, but everyone at this point can make their participation in the bounty even though the rank is still below Jr.member.
it applies only to some campaigns. If indeed there will be a rule update that must be applied by all managers to be able to participate in the campaign I think it will be better. The manager definitely has his own rules, but it would be better if there are suggestions from the forum to make rules that are fairer and better for everyone. The manager will then just have to run and develop the agreed rules.