I attempted to claim 4 powerful gear rewards from 4 different vendors on my second character and didn't get anything from them, even after receiving the dialogue that precedes receiving the rewards.
Now, I'm new, so I'm not sure if this is because I'm unable to do the weekly bounties more than once across multiple different characters, but I'm fairly certain plenty of people who are high power level couldn't get high without doing so, but either way I would just like to know whats up so I'm not wasting my time.
That is because you have two characters of the same class (Hunter). You can only obtain powerful rewards once per character class per award source. Once Hunter #1 claimed a powerful weekly bounty reward your second Hunter would only get a non-powerful legendary when they do it the second time.