Yes, ginger neutralizes stomach acid. This is why I would not use Ginger Bitters. They are using the ginger because it has powerful digestive enzymes, then they have bitter herbs at the end to kick up stomach acid. They would have been better off using the bitters as the primary ingredient then using the ginger in small amounts for the enzymes, but not at a level that would affect acid levels.
Therefore I would not use these but go with either the Grape Bitters, Chinese Bitters or Floradix Bitters.