I did a bit of poking around and will share the following quote from a web page about The 14th Annual DC Blues Festival.

Whether playing his own Hey Bartender There's a Big Bug in My Beer, reworking a Tommy Johnson blues like Big Road Blues into what it would have sounded if it had been written by Blind Boy Fuller or doing a Piedmont blues classic like Red River Blues, Warner Williams astonishes with his guitar mastery and touches with the soul and warmth of his vocals.

This would appear to answer the question as to authorship of the song.