What is a punt and why is the bottle made that way?
Historically, punts were a function of wine bottles being made by glassblowers. The seam was pushed up to make sure the bottle could stand upright and there wasn’t a sharp point of glass on the bottom. Today, they are really non-functional, decorative aspects of the bottle.
Punts are also used to fool the eye. Having a punt on the bottom means the bottle must be taller to hold the same volume. Some believe the punt implies a higher quality bottle. It IS most often associated with a heavier bottle weight than non-punted designs.