Hi John, yes, there is another volume dealing with the descendants of Robert Poage, the older brother. Robert's lineage had many more notable people than did John's. One of our distant cousins has Vol I and is available for look-up assistance. If you wish to write her, let me know.
My lineage, and my book, is Vol II- John Poage, the younger brother. The Bishop/Woodsworth genealogy is in two separate volumes and are marked Vol I and Vol II. Both were the result of the same effort by the authors but published separately. Vol I is about the descendants of Robert and is about 1,200 pages long. My Vol II is much shorter.
Vol I is available on Ebay and Amazon for about $100. They are reprints but will have the same information as the original. See: Ebay.com or Amazon. com for more. Good luck, VB