Less than two weeks into his move from Bournemouth, Semenyo scored a second goal in two games as City won the first-leg 2-0 at St James' Park.
The Ghana international was denied a second on the night by VAR and Bernardo said afterwards: "Happy but it is just one leg, we have the second at home. A very good result. It should have been 3-0 but we are quite used to this at the moment.
"I don't know what to say, I don't want to say too much because we know how these things work. I saw it, it looked really close to me but it is what it is. It is so frustrating because the last time we came here we also had a lot of decisions go against us.
"Even though we won it was just frustrating to be honest."
On Semenyo, he added: "He looks not just a very good player but also a very good guy which fits right in with the team. He is a fantastic guy who wants to help us. Hopefully he can keep going."