Is Stream via ethernet Superior to BlueTooth?

Wifi is different than BluTooth.  Wifi has essentially the same bandwidth as Ethernet.  The isseus as pointed out is whether you have a strong, uncontested signal. 

The use of a phone or laptop based Wifi analyzer to help sort that out is really useful especially in wifi congested areas. 

At home I have a mix of devices but for my serious music, work and Home Theater I only use Ethernet.

A proper network connection supports higher resolution than Bluetooth.   

As mentioned, bluetooth is a lossy format that you should probably avoid in a high end system. It's great for convenience though, but not ideal for serious listening.

Wifi is a different story. It can sound as good as hard wired ethernet on some components. Depends on the implementation. Even if it isn't as good, it won't be far behind, and is totally a valid choice if that's what works for your setup.