As far as I'm aware, the 2.4Ghz transmitter on the Phantom 2 does not have a CE / FCC mode switch.
The P2 Vision Rc controller beeps when you turn it on to indicate what mode it's in. The P2 transmitter doesn't beep.
Legal limit in the US is 1,000 mW effective radiated power on 2.4Ghz. In the UK the limit is 100mW.
I've no ideas what the output power on the P2 transmitter is, maybe someone has tested it ?