Bulbophyllum Elizabeth Ann 'Buckleberry' - am I doing it right?

[greenochre]

Hi! I'm an orchid newbie and recently bought my first Bulbophyllum - Elizabeth Ann 'Buckleberry'.
I put it in coco coir basket with orchid mix, but I don't know if it's the right thing. Should bulbs and roots be buried in the substrate, or rather be on top of it? What does the new growth look like?

I live in Barcelona - my air humidity is very high, the temperature at winter is 21-23 Celcius at the daytime and about 15 Celsius at night. I water it every 3-4 days by submerging the basket in the bowl with water + some fertilizer, this is enough to not let the sphagnum in the substrate become completely dry.

I don't have natural light at all, unfortunately, so I put it under the grow lights among other plants.

Advice is very welcome!