Is Stream via ethernet Superior to BlueTooth?

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.

Bluetooth ldac support exists for pc, which can essentially give you something close to cd quality.

Quality of the bluetooth hardware integrated in your mobo (or external) can vary significantly, however...i.e., your mileage may vary based on the latter, not the codec.