It depends on terms & conditions of specific bounty program as the rewards can be paid as in coins, e.g. BTC, ETH, etc., as in project's tokens. In order to get your bounty rewards you have to provide your wallet address. Use MyEtherWallet, Bitaddress and Neotracker to open wallets for ETH, BTC and NEO correspondently. Actually, it is enough in 90% cases.