From George Farris:
In 2015 when I was tracking William Bonnell on tax lists through several counties in Virginia from 1782 through 1797 I didn't find him for the years 1784, 1785, and 1786. We know he was in Albemarle in 1785 from other references, but assumed they were moving during 1784 (Spotsylvania to Albemarle) and 1786 (Albemarle to Rockbridge) and weren't on any tax list.
Recently, Binn's Genealogy has added tax lists for a few counties that had been missing previously, including Fluvanna. I had thought that William Bonnell might have been in Fluvanna in 1784 but he was not listed for that year. However, there is a William Barnel listed in both the 1785 and 1786 Fluvanna tax lists which I have attached. Fluvanna is adjacent to the southeast of Albemarle but not really on the migration route from Albemarle to Rockbridge so I'm skeptical about this being him.
Another confusion factor is a listing for a Fisher Rice Bonnel for the years 1783, 1784, 1785 and 1786 in Fluvanna County. I've never heard of anyone by that name and don't find him in any kind of search.