Greg joined the CAP as a cadet in 1973. He was a member of Crusader Squadron (TX-076) where he rose to the rank of Cadet Lieutenant Colonel before becoming a senior member. In 1981, he was commissioned as a 2nd Lieutenant in the U.S. Army and served as a cavalry platoon leader, cavalry troop executive officer, and artillery forward observer. Greg re-joined CAP in December 2001.

Greg has been the husband of Melinda Bowman (nee White) since 1984. They met in 1976 when they were both CAP cadets. They are the parents of three girls: Janeice, Glyn, and Elizabeth. The Bowman family has lived in Bentonville, Arkansas where daughters Janeice and Glyn were born, Lille, France, and San Diego, California where Elizabeth was born. They moved back to Texas in 1998. Greg works as a software engineer for Teradata (a division of NCR).