Charles was a free man and paid like any other soldier. I found his obituary :
Macon Telegraph, March 20, 1880 page 4
Charley Benger, a free man of color, died March 19, 1880. A fifer for the American forces when the British landed at Darien in 1813. A pilot on the Ocmulgee River. Fifer for the "Macon Volunteers" since their organization in 1825.