Can the river boat of Erhai Lake and Mei lake take a circle route that includes sitting on Wenchang Bridge dock as well as parking at Nanchang Dock?

According to the Two Rivers and Four Lakes (两江四湖) boat cruise schedule, boats can indeed travel in a circular route around Wu chang Bridge (文昌桥码头), but they cannot turn back at Wu chang Bridge pier. Instead, they will continue along the canal after crossing the bridge.

In other words, although you’ll be able to see the bridge while on board the boat, it won’t stop or change direction there; instead, it will keep moving downstream until reaching its final destination.