The wrinkles will not go away on the older of the pbulbs no matter how much you water. The bulbs are already giving up their energy (starches and sugars) to the new growths. Watering is not the problem there. New growth is what is making them wrinkle. If you are away for 4 or 5 days at a stretch then cut up some of the moss into 1 inch lengths and mix it in with the bark. That will help keep the media moist without it being wet. If this was a larger specimen I would pot it with bark only under the rootmass and then fill in the outer protion of the pot with a bark/spag mix so as not to create conditions where the center of the pot stays wet while the outer protion dries out too much. The outer part is where the new growth is and that should be kept moist at all tmes. Not wet. Just moist.
^ Makes a lot of sense to me now. I was thinking earlier that better to have moss at the bottom, or else the water will trickle out faster and less moisture will be retained, but I get your point about the benefits of keeping the moisture higher up in the medium. Thanks, James.