"With the lunch we drink wine."
Right. The verb is always in the second "position" of the sentence. Don't ask me why, I don't know why, but that's the way it is. In this case "mit dem Mitagessen" is the first, meaning the verb has to be second, forcing wir to go after. I think one of the only exceptions to that is the command form, where the verb is in the first "position".