I picked up a Encyclia cordigera in a 4" pot, and seems like a pretty hefty plant, REALLY packed in there. I have read about potting medium, but haven't seen about when to repot. Since it's a spring bloomer, seems like I'd want to do that now. By "really packed in" I mean I haven't replaced the plastic label stake because I didn't want to crush it or the plant.
Also, orchids don't get "root bound" in the way that terrestrial plants do. Having roots really tightly wound in a pot is usually an indication of a robust, healthy plant. No need to mess with it unless the newest growths are overgrowing the pot.