Mike, you made a very profound comment and many people today when doing seams skip about two steps.
A proper seam treatment does require about three to four skim coats over the tape for that nice un noticable seam. As you know on both sides of the full sheet of rock there are concave edges that should meet when running rock. This is to allow more mud and layers to fill in to keep the tape from peeling off in later years and with the proper floating trowel it will make a perfect seam. Maybe not or maybe so, your one layer of mud and a skim coat might cause the tape to buckle and peel in the near future.
Where applying the tape then applying after drying three more layers and sanding between will conceal and seal that tape and make a much stronger bond and union.