I am not aware of a comprehensive list of just Georgia troops that Galvanized but in Lillian Henderson's multi-volume set, Roster of the Soldiers Confederate States of Georgia, 1861-1865," she does note many of the soldiers that did joined the U.S. Volunteer Regiments that were considered the "Galvanized" regiments, however, she also mentions (when so noted in the Compiled Military Service Records (CMSR)) when they joined other Federal Regiments and the U.S. Navy.
I would like to make a correction in your last paragraph. It was six REGIMENTS and not six COMPANIES. A War Between the States Federal company consist of approximately 100 soldiers. A regiment was approximately 1,000 men at the time.
When information or a name was extracted from the various original records that is how the "card" was generated in the CMSR. I believe if you review the original muster rolls (at the National Archives) of the six regiments it may give you the regiment and state that the soldier was from.
If you don't have it already, you may want to review "The Galvanized Yankees" by Dee Alexander Brown. The bibliography may give you some added resources to review.
I hope this helps.
Gerald D. Hodge, Jr.
War Between the States Historian
Historian: 39th Georgia Volunteer Infantry Regiment