I'm not sure exactly what you mean. Do you want to gfet rid of the instrument cable(connects bass to amp) or the power cord(amp wall outlet). For the former you just buy a wireless system and use any bass amp and bass guitar. They cost $100 and up. For the latter I'm not you would need some small battery operated amp. I've seen them for guitars not sure about basses. They are cute but thats about it.
I really don't know much about them but if you do a search on this forum I'm sure you will find all sorts of information about which ones people like etc..
Why would you need the AMP to be wireless? Now , I run my bass guitar wireless, but there is no need for the amp to be wireless.
Ah this is why I love forums... half answers that don't really help.
Wireless amps, I have never heard of such an amp with a built in wireless reciever. What you need is an amp, and a seperate wreless reciever.
A wireless system is a seperate component which has a reciever (a rack mountable unit or as a unit which can sit on top of your amp, or on the floor with your effects chain) and a transmitter ( a body pack or "bug")