There's no reason to repot it again if you potted it in August. The roots that are growing above the mix are aerial roots. Some phals prefer to have some of their roots out in the air. In nature all of the roots would be growing out into the air. When you water the plant make sure you wet the aerial roots well. In fact, if you like misting, you can take a little plastic spray bottle and mist the aerial roots regularly. That way you can give the plant moisture without risking root rot. So just leave the plant alone and let it grow the way it wants to. Good luck.