No, Joe Teti and Matt Graham (new member of the show), are not related at all. They have quite conflicting views on survival.
It all depends if you are wanting to watch new episodes or old ones. You can watch them from Discovery Channel or you can watch them from many different websites. But if you search Dual Survival Full Episodes, click on Discovery Channel. Click the button that says Full Shows at the top left. Then above the episodes on the right there is a arrow button pointing to the right, click it util you find Dual Survival, the list is A-Z. Click on Dual Survival and it will have full episodes.