Phew...
One wireless switch is certainly possible and the easiest solution, though I'm not absolutely sure whether it's the most reliable one. I prefer to keep things wired whereever it's possible...
Other than that... latching relay with 12V coil and push buttons wired with phone or door bell wire...
If you're looking into bus systems there's always EIB... but that's high tech, most likely EXPENSIVE and you need a laptop + the EIB software to program everything. I also have to admit I never heard of wireless EIB switch actors... but that might work.
Personally I call it "European Idiot Bus" 'cause it's so complex to install and program...
Basically You have sensors and actors, both of which connect to the same bus. Sensors can be push buttons, thermostats, motion detectors, you name it. They're all bus powered. Actors are switches or dimmers that switch the 230V power.
Everything is connected to one bus cable and each device gets its own address. During programming you have to tell the system "Sensor 001 is used to switch channel 2 of actor 010" for example.
