A good first step would be to find out what type of glass you want to
cut. Not all bottles are the same. Those built to withstand pressure,
such as beer or champagne bottles, are often tempered and harder to cut
without unintentional breakage.

I'd be inclined to visit a glass shop, particularly one that does
stained glass.

RubEric wrote:
I wish to cut a round disk out of several wine bottles. The bottle
has an etched figure I wish to remove for another purpose. I have a
virtually unlimited supply of these bottles and they have no value so
I can afford to make mistakes.

How should I go about cutting a 2 inch diameter disk out of a bottle?
I had thought to use a diamond blade on my Ziptool to cut out a
rectangle and then wet grind the removed piece.

A diamond hole saw may be a possibility, but they are EXPENSIVE.

What would you suggest?

Thanks, Eric