The 27-year-old, who returned to Kotoko four months ago after terminating his short-term contract with Egyptian club FC Smouha, had a two-week trial in Tunisia before he was offered a contract.
"Honestly, I'm very excited to sign this contract because I've worked really hard for it," Bancey told Goal.
"I had to train with the team for several days in order to prove to the coaches and management that I deserved the opportunity to play for the club.
"Now that I have signed the contract, I am hoping to hit the ground running and score as many goals I can to help in achieving the set goals. Last season, ES Zarzis finished 12th on the log but a top half finish in this campaign would be great."
He added: "The supporters should be patient with me since I'm new to Tunisia and the club but as soon as I adapt to the system, they will know I'm really an asset for them."
Bancey spent three and half years at Kotoko, joining them from Ebusua Dwarfs in 2013. He became the club's topscorer after hitting 12 goals during the 2013-14 season.