i participated in 22 translation bounty and 3 or 4 signature and i didn't earn a cent so its really depend of the project and what you participate in
it depends on what bounty you joined because 1 of my friends join 2/3 translation bounty and he earns around 2~3 Bitcoins.
last year i joined signature bounty and i earn around 300~800$ for 3 months
You are right it completely depends upon the company we choose because last year we have seen many scams which they have not given any profit to the bounty people. Sometimes it is impossible to make 1 bitcoin through bounties. Nowadays, finding legit bounty is a very tough job.