The bar code number only identifies the bottle. Its just a number. The number is read by the scanner and a database searched for the details associated with that number.

Without such a database, the barcode number printed on a wine label is useless. CT's database contains many of the numbers with their details but it is not exhaustive although it can be updated by users.

I do agree completely, the scanner software needs to be able to match against a database of UPCs