The WTSO writeup doesn't specifically state it's from Alexander Valley, only that it conjures up that taste profile, however, technically being that Alexander Valley is in Sonoma Co., I suppose one could say it's from Sonoma Valley as the label states.
The reason Ty deemed it a cuvee:
He explained that for his Winemaker’s Cuvee he was going to make these from the best tasting single vineyard blocks to blend into a very special Cabernet. His philosophy is that the best of the best from individual blocks with their unique characteristics when blended together would produce a blockbuster wine. The Caton Vineyard (which encompasses all his single blocks), is hillside Cabernet in the Mayacamas Mountains, with multiple sun exposures, each block producing a distinct wine from each part of the property. The main components, which Ty also bottles as exquisite single block wines, are: Big Hill Block, Upper Bench Block and the Little Hill Block. This lush Cabernet was aged for 14 months in 40% new fine French Oak. This rich Cab exhibits a dark purple hue with black cherry, black raspberry and vanilla on the nose. The palate screams Alexander Valley with generous fruit including dark cherry, currant, plum, cassis with hints of vanilla and coffee. The finish is long and pronounced, with perfectly balanced tannins yielding a silky mouth feel.
Obviously there's a lot of Ty haters here, and I honestly haven't tried a lot of his wines, but this is one of the best deals on his cab that I've seen in a long time. For this price, I'm comfortable trying one now, and lying a few down to see how they age. His 2001 Merlot aged quite well. Sadly, IMHO, WW prices have been lackluster on Ty's cabs and his upper end reds for some time. I sampled some of his reds, including the aforementioned 2001 Merlot, and a newer vintage TyTanium at WineDavid's BBQ last summer. They were all tasty, albeit absolutely new world in style.