Canaries Hall of Fame Member on Wales' Euro 2016 journey
The former left-back made over 400 appearances for the Canaries during his playing days, while also representing The Dragons' national side on 41 occasions - going on to form part of the Welsh coaching staff in the 2000s.
Wales reached the last four courtesy of a superb 3-1 win over Belgium last weekend, and writing in a column for the Daily Mail, Bowen said: "You look at the side and you see a team growing together.
"They are strong behind the scenes and that’s important. The Russia game showed to me how they had grown having gone into that after losing to England.
"The way they passed the ball spoke of confidence and belief and togetherness. If there were doubts or issues within the team that's when you would have seen them.
"They are just playing their football and enjoying it. That's crucial and not all teams at this tournament have been able to say the same.
"Wales’ momentum is such that they will go into this game thinking they can win if they stick to what they've been doing. That's a priceless mental state for any team to be in, particularly at this stage."
Much of the build-up has been centred around the prospect of the two most expensive players in football history facing off, with Real Madrid pair Cristiano Ronaldo and Gareth Bale looking to lead their respective countries to glory.
However, Bowen says Wales must avoid focusing on individuals, for either side, in order to make history by reaching their first ever major international final.
"They must not obsess about Ronaldo and Chris [Coleman] won't let them," he explained.
"Portugal have other quality players we know about, and Nani in particular is having a good tournament. However, I don't think Portugal are as good a side as Belgium and Wales have already beaten them.
"For us, Gareth is the star of the team but he's probably played at about 70 per cent of his best out here. What has been pleasing is that other players have stepped up.
"We've not been a one-man team and that is because other players, like Joe Allen, have come to the fore. Wales are facing a side they can beat in the last four of the European Championships; it's an amazing thing to say, but it's true."