Is new wine in old bottles a good word or a bad word?

This is a compliment and a derogatory one.

New wine in old bottles is used to describe a new idea or concept, which adopts the traditional form, but it can be widely accepted and spread, so this idiom is positive. This idiom is derogatory. It is used to describe a new product or technology that adopts the traditional appearance or packaging, but in fact there is no innovation or improvement.