What is the wisdom behind prohibiting sitting with a wine-drinker, but not prohibiting sitting with a pork-eater?

There is no difference in ruling between sitting with someone who commits one sin and someone who commits another. Just as it is forbidden to sit at a table where alcohol is served, it is likewise forbidden to sit at a table where pork is eaten, due to Ibn Taymiyyah's statement: "It is not permissible for anyone to attend gatherings of evil by his own choice, unless there is a necessity," except if it is for the purpose of denouncing it. One of the objectives of this legislation is to protect the Muslim from deviation, because a companion is influenced by those he sits with, whether positively or negatively. This woman should be invited to Islam, and its virtues should be explained to her, for whoever causes someone to be guided to Islam will receive a great reward.