bought new oncidium, does it look healthy?

[BobInBonita]

It's hard to say from the pic, but the bark looks really dark. It might just be wet after being buried by the sphagnum, or it might be starting to decompose.

I wouldn't put more bark on top. The level that you see is the level that it has been growing at. Covering it can risk keeping the PB too wet.

IF the roots look healthy and the bark isn't decomposing, you can wait to repot, but if the roots or medium are starting to go, the sooner the better.