I can't say I know the wines from the region at all.
There are some great wines from the Piedmont region, namely the Barolo and Barbaresco. And the area around Asti is known for the Spumante, though I would not recommend it.
Truly, there are already a lot of sites on the list related to winegrowing. The vineyard connection on this website lists 25 sites, for five of them the justification criteria exclusively refer to winegrowing: Saint Emilion, Tokaj, Alto Douro, Pico Island, and Lavaux. So I think vineyards are already sufficiently represented on the list.
Moreover, the recent proposals mentioned by meltwaterfalls seem also to refer mainly on the topic wine.
Langhe-Roero-Monferrato was deferred in 2012. ICOMOS considered that the site has potentially OUV, but criticized that „this has not yet been fully demonstrated because of the property's definition. On the one hand, it is incomplete because it focuses solely on the vineyards' aesthetic aspects and omits important built components (monuments which have played a role in winegrowing and winemaking history, expertise represented by the cellars and wine houses in the urban environment, etc.). On the other, it offers a vast collection of landscapes, undeniably of high quality, but relatively similar and insufficiently critically assessed for their intrinsic winegrowing and winemaking value"
So a revised proposal probably could have good chances.