Jack Poust & Company, Inc. has some vegan options

Company email (March 2015):
"Below, please find the response to your question from our supplier in Portugal:

In fact only the Late Bottled Vintage & Vintage Ports do not carry an ingredient of animal origin. These wines are not clarified or even filtered. All other Ports are clarified with products from animal origin ( gelatin from fish or from pork).

We are not really aware if this info would be helpful but the gelatin comes in and goes out from the wine. It does not stay there. Nevertheless it has contact with the wine.

And we do not bottle or manufacture anywhere else in the world except in Douro."