If you have a stem with a new plant starting on it, wait until there are little leaves, and roots a couple of inches long, then yes, you can 'air layer' it into another little pot.
Don't forget that orchids are mainly epiphytes, so the roots really don't collect all that much nutrient. Spraying the leaves with water, and adding a little fert to the spray water will establish it quickly. Once it's been in its own pot for a while, and keeping on growing, you can cut the stem from the mother plant. The leaves may get wrinkly for a week or two, but don't despair, it will revive.
My phals all grow with at least a portion of the roots sticking out into the air.
