They aren't, as post #51 points out. Their literature is full of references to Zion as the promised land, Babylon as the decadent world, and Haile Selaisse himself as the Lion of Judah.
Rstafarianism, and Reggae music in particular, took hold as a protest against colonialism -- so it sounds like this particular "Rasta" latched on to the Jews as his oppressor and incorporated it. It's not generalizable to Rastafarians, let alone Jamaicans.
Thanks ~pandora~