Canaanite Reconstruction focuses on the Canaanite peoples of the Bronze Age and their religious practices, as best as we can tease them out of the limited amount of archaeological evidence we have available. The Canaanites were never a monolithic bloc of people who referred to themselves as such--there were many groups of peoples who shared the same culture (including the peoples who later became the Israelites).
Look here for a basic introduction: canaanitepath.com/stele.htm
When speaking of various forms of non-monogamy...it ain't poly if you're just fucking around.
While polyamory, open relationships, and swinging are all distinctly different approaches to non-monogamy, they are not mutually exlusive. Folks can, and some do, engage in more than one of them at a time--and it's all good.