PIC32mx UART to Bluetooth RN4020
Your code appears to work fine (apart from a bit missing from the interrupt routine, which I assume is just a copy/paste error because it won't compile as-is).

However it only sends the serial message once on startup, then waits forever. The PIC starts sending data about 1ms after coming out of reset, so if both the Bluetooth and PIC are powered up at the same time the Bluetooth module might not be ready in time to receive the message. 

For debugging I would send the message repeatedly in the while() loop, with a delay of about 1 second before each transmission. To prove that the PIC is sending data you could wire an LED (and series resistor) from the TX pin to Vcc. The LED should flash briefly in time with the message. If this works but the message still doesn't get through then check the wiring and configuration of your Bluetooth module.