I think not now possible to eran bitcoin for your lower rank with the bounty program. I see your rank ,you have Newbie member. You can eran BTC but Signature campaign. Definitely Newbie member can not accept signature campaign.
So now you can increased your Rank and activities. Then you will join Signature campaign.and you will got to eran BTC.

Present in the others way to eran BTC . Yes you can eran BTC for trading and investment work. Absolutely personally I support them trading. So you will try them.