In order for anyone to answer to your question, you should first quantify how fast it takes you to finish any of the given tasks that are offered within a bounty campaign.
Social bounty is the easiest and requires the least amount of time, however as the percentage of rewards distributed towards this type of campaign is less, and the amount of participants is high, it takes you less time to achieve less.
Translations could be the bacon bringer in this situation hence you do a one time job in exchange for some big bucks. On the other side, the activity is more daunting than sharing social media posts, but also requires a bit of knowledge in order to proper translate a document.
By measuring how much time it takes and how much money you are rewarded with at the end, you can as well measure the risk you take, because not researching the project you're promoting might cost you several, considerable hours of work.