If it is a good campaign and all goes well, you should expect payments after about one month after the end of the bounty. You may need to wait another month to exchange your tokens for real money in the exchangers. Usually, that's the finish line, so, yes, it is normal to wait 5 to 6 months for your reward but usually it demand less times maybe 3-4 month in most of the case.
If a Bounty camapign is going to last 6 month ask yourself about the success of the project and look the market before trying to switch to another ICO