While Vendikar was settled by the people of Eminiar VII, there's no indication in "Patterns of Force" that the Ekosians and Zeons are meant to be related. The dialogue suggests that they developed independently -- the peaceful Zeons developed spaceflight, came to Ekos, and shared their technology with the backward, warlike natives they found. Of course, in the larger Trek context, we can surmise that they were likely related to each other and to other humanoids, but the episode assumed they were separate.
