I unfortunately never got the whole story, but I believe it is a French regulation that bottlers tell you where they do the bottling (and that tells you where they got the grapes).

On the chateau: grapes come from the vineyard at the chateau.

By the properitere: grapes could come from lots of vineyards.

In the cellars: God knows where the grapes come from.


Any French folks here who can chime in?