The Simulink Hardware Support Package does not explicitly provide a block to connect to the Pi via. Bluetooth. However, there are many other ways to connect and send/receive data to/from the Pi. Also, you can write your own drivers for the hardware if you have a specific workflow you want to implement. The following article discusses this approach:
There is another discussion on MATLAB Answers that points out how you can use Bluetooth with Raspberry Pi: https://www.mathworks.com/matlabcentral/answers/266991-is-it-possible-to-use-bluetooth-with-matlab-raspberry-pi
