I have seen this copy forum of Bitcointalk on bounty campaigns but never paid attention. Maybe it will be useful for high-rank bounty hunters to merge their forum account in bounty spreadsheets but I am not convinced to open a new account there. Anyway, they accept the fact about which forum gets more traffic from crypto users.
I don't find any big reason why we need to register in that website using our username here just to take advantage on the rank. Is there anything that forum offer other than they have bounty there the same bounty that we also have here?
For me our bounty thread is enough unless you are project owner that want to advertise your project to different from thats might be very helpful for you.
Simple answer: you can join double the amount of bounties. If you find a bounty that on both forums that you would like to join, you can join on altt, and use your btt account to join another bounty.