The Exiles coach told BBC Sport: "Gavin's got another five years of real good rugby ahead of him and it's nice to see him doing well.
"I'm delighted for Gavin, he had a tough time in Wales and just recently he's had a good year up here. He's relaxed, he's enjoyed himself and he's made an impression.
"He's been out of the spotlight and been getting on with his rugby as best he can. Gavin's been a real good player for us and he's certainly made an impression when he's been on the field. He's obviously turned heads, especially at Bath. It's a really good club, Bath, and I'm sure he'll fit in well there."
Henson has been capped 33 times for Wales.