Many of the varieties Pine Island is growing came from California and they just re-named them. Looking at the links (file name) for some of the photos reveals the original name/source. Several are Paul Thomson varieties and one is a variety from Quang Ong. I think posted some of the synonyms earlier in this thread.
Tony, your yellow dragonfruit looks like it is coming along well. You've had to be patient waiting for that! I've got a plant also and they only way I'll be able to get mature fruit is to keep it in my greenhouse or a tunnel.
Here's a very good page on cultivation of dragonfruit in Vietnam:
http://trunghieufruits.com.vn/index....mid=59&lang=en