Usually you earn tokens worth very little with airdrops (but you don't need to do actual work). Bounties it depends, I have earned very little sometimes (worthless) or I have been pleasingly surprised with more than USD 500 worth of tokens. I only do bounties for projects I like and invest myself, it is a way to earn more tokens you like on top of your investment, like the cream on top of the pie.
Its good to choose two of them because if you join to the bounty you need to wait a month then airdrop is everyday earn but choose bmvery will to airdrop because many of time are scammer so it grate to choose to of them to double income.