You must add the name at the time of the reservation for it to only count as one guest certificate, or 1 $99.90 fee if your out. You need to cancel and rebook it to get name on only using one at this point. That's the only way to do this. As long as it is added during booking process this is one reservation (even if split into 2 parts) but once it's booked it counts as 2 to make changes. Hope this helps
This is a YMMV situation. It depends upon the VC you get, the more senior ones can apply an over-ride. If you book the same day you can get a guest name added to the split reservation, many here have done this often. Sometimes you do have to call back and/or ask to be passed over to Owner Care.
However, I believe the original poster was asking about the Reservation Transaction Fee, not the guest confirmation fee. Should only be 1 fee if all transactions are conducted on the same day.