How to connect your bluetooth phone to a hi-fi?

You have to use Bluetooth Audio Receiver.

For example like:

= Anycom BAR-10 = http://www.aria.co.uk/Products/Peripherals/Bluetooth+Devices/Anycom+BAR-10+Bluetooth+Audio+Receiver+-+Connect+your+HiFi+to+any+Bluetooth+music+source%21?productId=29618