Wow, those are nice size babies, Becky! In the orchid world we call those 'keikis' which is a Hawaiian word for baby.
I'd suggest instead of potting them up, you could just mount them on a piece of wood. They seem to be doing so well just waving around in the air there, really there is no need to bury the roots. Orchids are epiphytes, well designed to collect water and nutrients from the air, so whatever great care you've given those plants, just keep on with it. You'll notice that when you water or it rains, those roots turn from white to green, as they absorb the water.
Here are pictures of a couple of my mounted orchids. The important thing with a Phal like yours is to make sure the crown of the plant is on a slant or pointed downwards so that water never sits in the cup of the leaves. People tend to want to mount or pot them standing straight up and this can lead to crown rot in a spell of wet weather.
You don't need to cover up the roots. They will find their way to the mount and attach themselves. Just find a sturdy piece of bark or rough wood, put on a little cushion of coco fiber (like the stuff used for hanging basket liners, only pulled apart so it's airy) and tie the keikis onto the wood firmly so they won't wobble around. I used strips of bird netting to tie these on. Other people use rope, wire, panty hose, even zip ties. After about a year, the plant will be well attached, and you can remove the tie material if it's unsightly. I use slabs of cork as a mounting.