the traditional, and cheaper way, to filter wine is with the following animal driven Ingredients:
therefore if used, it is not vegan. sometime it changes from year to year, which can be difficult to follow.
an example of a company that keeps their info up to date is "Sutter Home". and luckily they are inexpensive and widely available in the U.S.
today a lot of vineyards use an electric filtration systems.
a good resource to check changes is Barnivore at barnivore.com