(NVR) - Four decades after Domaine Chandon planted its first vines on Yountville’s doorstep, the town is looking to bring its neighbor winery one step closer to annexation.

On Tuesday, the Town Council will vote on a request that a Napa County commission add Chandon’s visitor building to its sphere of influence, a step toward adding the winemaking center to its territory in the future.

An addition of the Chandon building would be Yountville’s first expansion or boundary change since its incorporation in 1965. State law defines a sphere of influence as the “probable physical boundary and service area of a local agency,” and any annexations by a town or city must be consistent with that territory.

Yountville’s expansion proposal covers only the developed portions of Chandon’s property — its visitor center, offices, tasting room and the Étoile restaurant — and not the winery’s vineyards or other agriculturally zoned land.

In a staff report to the Town Council, Associate Planner Sandra Smith said Chandon’s firm links to Yountville’s daily life are reason enough to formally absorb the winery into the town.

The sole vehicle access for the winery’s estimated 250,000 annual visitors is within town limits, and the Yountville Trolley provides free shuttle service to the winery — the trolley’s only stop outside Yountville’s boundary. The report also cited Chandon’s role in local organizations such as the Yountville Chamber of Commerce, Little League and Kiwanis Club as further reasons to fold it into the town.

In addition, Domaine Chandon has been connected to Yountville’s sewage treatment system since a 1991 pact in which the winery also began accepting the town’s treated wastewater for irrigation. (Chandon continues to treat its agricultural wastewater on-site.) That deal followed the winery’s expansion of its office space a year earlier.