BOSTIC/BOSTICK and BOSTWICK listings in one family line is usually through the lines out of SC.Less so from NC.
Nevertheless, I am familiar with the variable spelling of the surname in my wife`s maternal line.
Also to add to the mix is her maternal line is tied to the LASSETER/LASSITER line. [NOTE here also is the variable spelling.]
I am aware of Willard D. and will have to look for your Willard B.
Evidently, Joseph A. BOSTWICK in Terrell Co GA is kin to your Willard.Joseph A. married Pinkie LASSETER in DEC 1881 as your Willard married Della LASSETER in NOV 1881 both in Terrell Co GA.Then there we also see your George W. marrying Fannie BOSTWICK in DEC 1881.
If there were BOSTIC/BOSTICK/BOSTWICK in and around the Terrell Co area more than likely just off the top of my bald head I would venture you looking at the large family in the Stewart Co GA area to start with.
These folks would eventually lead you back to Jefferson Co GA and then back to Newton and Morgan Co GA.From there they go to Wilkes Co GA and then into the Rev. War in NC and VA. This family was into teaching, law, and craftsmen.
The other branch would be in the Montgomery Co GA area back into Washington Co GA. They also go into Jefferson Co GA back into Richmond Co GA and into SC and the Rev. War in SC, NC, and VA.This branch of the name was into Rice farming.