Promenaea silvana is one of my few species plants, and perhaps one of my first.
I believe I got this plant late last summer, so about a year ago. I repotted it this winter and discovered its roots had suffered under my care, so much so that a pbulb and growth fell off. I potted that 'division' up however the new growth on it died and now the little wrinkly green pbulb is just sitting there, guess I'll have to wait and see what happens.
In the meantime, the main plant was almost immediately grateful it seemed for the repot and threw out a couple new growths. It wasn't long before a spike appeared this spring. HOWEVER, that spike has taken FOREVER to bloom. It all seemed to be growing well in my south-facing window with watering a couple times a week, especially once I saw the spike. The development of the bud into a bigger bud took a very long time. I was worried more than once that it was going to blast b/c the spike and bud were mostly a pale greenish-white. I did ultimately move it outside though I would bring it back and forth when the weather was questionable since it was in spike. I'm sure this didn't help.
Funny though as I go back through some notes while I write this I see that I first discovered the spike in April so maybe it hasn't taken an unusually long amount of time to bloom rather I'm impatient...
It's in a very small 2" clay pot with a coconut choir, bark, moss mix. For the late winter and spring it got rather bright light in a south-facing window where it was a little protected by other big plants around it. It's been happiest with me watering it a least every couple of days as it tends to dry out fast. When outside it received rather bright light for morning and afternoon with some shielding by other plants so it doesn't get a lot of direct light though admittedly I'm almost certain it gets some.
I will also add that since March I've been using K-Lite and I did as Ray suggested in April (or was it March?) and for two weeks I used KelpMax at EVERY watering. And much of the time it has been outside it has rained and the humidity has been rather high.