I believe I have records that will help you with this family. See http://www.geocities.com/fcullom/ephraimbowen.html
You might want to drop back to http://www.geocities.com/fcullom/ and explore the entire family. I descend from this line of Brunswick Co/Lunenburg Co/Mecklenburg Co, VA Bowens, but not from Ephraim Bowen. Ephraim was clearly the father of a William Bowen, and it appears he was the same William Bowen found in Nicholas Co, KY later.

Hope this helps.