Bowen, 45, finds the chemistry the couple shares "sexy" and it warms her heart, reported Us magazine.
"He's like a caveman with her. It's sexy! I love it. She's so strong, and so (used to) calling the shots all the time, and then you see them together and there's a part of her that kind of melts.
"It just warms your heart when you see that, because it's not all the time that you can tell that there's an aspect to this relationship that's very - how shall we say? - primal," she said.
"You're like, 'Oh, Sofia, what do you want for your wedding shower? And she's going to be like, 'Ay, I want a toaster and some plates,' she joked.
"She has a beautiful new house. And her to-be husband is a minor deity - or a major deity."
Vergara and Manganiello, 38, are set to get married on November 22 at Florida's Breakers Palm Beach resort.