the bbj is going all 135 - period. should be completely transformed in a couple of months. couldn't sell them, so we'll charter them - phones ringing off the hook.
as for your original question, all planes and crews are 135 qualified. simply because you never know when or where something will pop-up.
generally, netjets doesn't do straight charter (where someone calls up and rents the plane). those trips are sent to the ejm division or sold off. like the above post said, we mainly do the marquis charter program. also, there are some instances where a new owner's money hasn't "cleared" yet and they run him as a charter customer, but on our fleet. also, some owners put a deposit down on a share, but there isn't a plane available to sell, so they're run as charter, too.