Both men have been linked with Manchester United, with Semenyo also interesting PSG and Tottenham.
But Tiago said of the attacker: "Antoine has been amazing this season.
"I think he's a lovely player, a lovely boy. For us it was amazing to feel that he would be happy to stay one more season even if other clubs were around him.
"I think he scored eight or nine goals this season, so we couldn't be more happy."
Tiago also said of Iraola on talkSPORT: "I think what Bill (Foley, owner) said was exactly what I said in the interview that I did with Sky.
"In Bournemouth, from the receptionist to Bill Foley, everyone wants Andoni to stay. So we will do our best to keep him.
"I think Andoni is happy in Bournemouth, like you guys know every time he jumps in the press conference.
"But we know how football is, so it's something that we will discuss internally and of course we hope that he's going to stay."