Getting Code onto Arduino Bluetooth
The ArduinoBT, after pairing, exposes a virtual serial port that you can use.

After that, you connect to it using the Arduino IDE over that virtual serial port.

So yes, you need a Bluetooth receiver on your PC for this to work, as the virtual serial port used for programming (typically provided by a virtual serial port over USB on a conventional Arduino), is now provided via the Bluetooth connection.  You'll definitely want to use that instead of a ICSP programmer.

If you don't have Bluetooth on your PC, there are addon USB adapters that provide it.