I would suggest copying their Dragon Fruit growing configuration for best fruit production results.
Their configuration consists of:
(1) A circular wood pole that goes through the center of a large Plastic Pot, and into the ground.
(2) The Pot (with pole going through it) is filled with quality dirt
(3) Several pieces of the David Bowie Dragon Fruit are planted around the pole (which, yes, is vertically inside Pot going into the ground), and touching the pole.
I have the David Bowie Dragon Fruit. According to P.I.N., it's very productive although the fruit size is smallish, with a quality sweet taste. Based on their description, I decided on getting this variety.
My configuration is similar but omits the large Potting Pot, which I believe may have been a mistake on my part.
For the past 3 years, I've been getting beautiful flowers, but so far no fruit. I'll probably give it 2-3 more years to produce fruit. And, if no fruit in 2-3 years, I plan to exactly copy the P.I.N. Dragon Fruit Configuration described above, and give the 'David Bowie' Dragon Fruit Variety one last chance.