How does it look? Last time I bought some there was a lot of lumpy bark in it, but then orchids grow in trees.
I found the same thing. My shop bought phalaenopsis have always been in a rough bark.. chunky, and large enough to keep from falling out of the holes all along the side and bottom. But I also recently picked up a bag of compost specifically for phalaenopsis, and it looks like a rough garden compost.. almost soil-ish. I haven't potted mine on yet either.
A friend of mine grew his on the little clay balls they use in hydroponics(?).. looked like little tiny round terracotta marbles. They seemed very happy in that. Looked pretty too.
I make my own compost. I go to the woods find an fallen tree and strip off the bark bring it home and dry it in the oven overnight mix in a little charcoal and that's it.
Not sure why the charcoal just remember reading some time ago to add a little.