Last time we looked at the term "Vinted by" that may appear on a wine label indicating that somebody else grew the grapes and/or produced the wine. The sellers simply put their name on it.
A step up is the situation where the winery and the winery's own vineyards are not in the same viticultural area. Here, the winery may designate that the wine has been "Proprietor Grown" on the label.
In the best of all cases, that is becoming rarer, is when a bottle's label identifies that it is "Estate Bottled." This means the winery produced 100% of the grapes used to make the wine, and the grapes were pressed, fermented, aged and bottled in the viticultural area stated on the label.
When looking for “Estate Bottled” wines from France, look for "Mis en Bouteille au Château," "Mis en Bouteille au domaine" or "Mis en Bouteille a la Propriete." In Italy, it's bottigliato all’origine, while in Spain it's "Embotellat a la Propietat" and in Germany look for "Erzeugerabfüllung."
Estate Bottled wines generally are of higher quality and therefore a bit more pricey. But, while a lot of information on a wine label is actually marketing, you can trust that an Estate Bottled wine has been entirely made the label's winery. Cheers!