That's too much for a bounty rewards. Waiting for too long for the bounty rewards to be given will make you speculate that they won't pay you. The longest time i wait was only 1 month and i it's a headache if bounties will be given that long. I usually read some bounty campaigns rules before i joined because sometimes they indicate on how many days will the bounty will be given and most of the bounties i read was only at maximum 60 days.