The Dane, who underwent loan spells at Sunderland and Juventus over the past two seasons, made his first start for the Gunners in two years as they advanced to the fourth round of the Capital One Cup on penalties at The Hawthorns.
Bendtner, who failed to find a new club during the summer, scored his side's opening spot kick, and Wenger was pleased by his all-round display.
"I thought overall he had a good game," Wenger said in his press conference. "For a guy who has not played for such a long time, and on his own up front, he did very well.
"One thing you don't question too much with him is his confidence. I believe for Nicklas, the most important thing for him is to stay fit. As for the rest, he has the talent.
"It is important that he is now consistently present and works hard physically. He has top qualities."
Arsenal will host Chelsea in the next stage of the competition.