what bob marley brother with jimi hendrix?

You can find a relation as a curiosity: in his first tour, when Bob Marley was an unknown and Jimi was a star, the Producer of the tour didn't want european audience to take Bob as a folkloric musicians, but as a rocker. As a result, we can hear some live recordings where Bob Marley present the band saying "this is Trench Town Experience".

no, they weren't related.