The Scotland international is wanted for a second month by the Championship club.
"We'd like to keep Chris for another month," said Bristol City boss Gary Johnson. "I speak to Mick McCarthy after every couple of games to let him know how Chris is doing. He is a great lad to have around the club, on and off the field. Wolves are in no doubts about our desire to keep him for another month and now it's in their hands.
"It was always going to be a month-to-month loan. He's still got three games left and we'll keep the dialogue going with Wolves.
"He's a great lad to have around the club, on and off the field."