We do, all the wine we make and sell is bottled at the Château.
You can check this on any French wine as it must be stated on the label. The words “mis en bouteille au Château” will be on the label if the wine is made and bottled at the estate. You cannot use these words for any other case
The label generally can be an indication as to the quality level of the wine, and whether it was bottled by a single producer, or more anonymously and in larger quantities.
“Mis en bouteille …”
“… au château, au domaine, à la propriété”: these have a similar meaning, and indicate the wine was “estate bottled”, on the same property on which it was grown or at a cooperative (within the boundary of the appellation) of which that property is a member.
“… par …” the wine was bottled by the concern whose name follows. This may be the producing vineyard or it may not.
“… dans la région de production”: the wine was not bottled at the vineyard but by a larger business at its warehouse; this warehouse was within the same winemaking region of France as the appellation, but not necessarily within the boundary of the appellation itself. If a chateau or domaine is named, it may well not exist as a real vineyard, and the wine may be an assemblage from the grapes or the wines of several producers.
“… dans nos chais, dans nos caves”: the wine was bottled by the business named on the label.