Coey, as long as it's a wee little spike you shouldn't have any trouble at all. Just don't knock it off while replanting the phal. I would say the earlier in it's development the better. I would up the watering a bit after you repot. Old bark retains a lot more water than new bark so you may stress the phal if you don't make sure it's getting the same amount of water that it was so happy with before the repotting. And then check it every couple of days until you establish it's new water requirements. Start the repotting by soaking the new bark for at least 30 min and at most 24 hours before you're ready for it. That will insure that it's good and moist. Also, chances are that you won't need a bigger pot so just repot with new bark in the same pot. But it wouldn't hurt to have one size bigger on hand just in case you get in there and it's root bound.

Thanks Claire!