Is there official content regarding the story of Judas Iscariot and what has happened to him in Vampire lore?
This wiki entry says that the Bashirite bloodline of the Ravnos believe Judas was cursed by God with vampirism. Sadly, there's no citation on that, and after checking through Jerusalem By Night (the only book I could find as a citation for anything about the Bashirites), there's nothing in there about Judas. The book in fact studiously avoids making any connections at all between vampires and the life of Christ. So, I'm at a loss as to where that information actually comes from, and I don't know if the text treats it as a real thing or a misguided belief.
There's a group (well, one in each line) called the Children of Judas, but they are only using the name metaphorically (one as a reference to the necessity of evil and the other as a reference to a famous person who committed suicide). They don't seem to claim any special relationship with the actual Judas Iscariot.