I work with bounty more than 2 years and it seems period of paid more longer that be in 2016.
It usually takes about 1-3 months after the ICO ended for the bounty to be distributed to the participants and after that we wait a little more for the token to be listed in an exchange and have volume to be able to trade. Distribution really depends on how successful an ICO is, some ICO not reaching their soft cap does not give bounties to their participants, while some ICO not reaching their hard cap extends their token sale then does the bounty distribution afterwards.