I grow mine in bright light like catts. I find Dendrobiums to be so difficult to understand. I'm still trying to figure out winter rests for some of mine. Oh well, that's half the fun, right?
My dendrobium hybrid (phal type i think) got a spike after i put it in a fishtank with good lights (two 100W high pressure sodium). Empty fishtank that is...hehehe
I need to keep the orchids there over the winter due to the darkness and dry air.
And the funny thing is that it is growing the flower spike from a old cane! It is growing 3 new canes and flower spike at the same time
So i think the light is really important to get the plant to flower