I realize he is in the region, but he is pointing out the fact that Syria has a Sunni government and Iran has a Shia government. But those in no way seriously effect the relationship between Iran and Syria.
http://www.haaretz.com/hasen/spages/827017.html
Iran and Syria have stated publically that they have an alliance. Iran has sold Syria weapons. They share the common interest of protecting themselves from Israel and US (their words). So, the fact they share different religions has nothing to do with their political relationship which was the crux of Infidel's little jab.