First off, be aware that there is only so much that can be done in terms of bringing down the latency: the network is your main limitation here and for large distances is just physically impossible to get the packets on time (i.e.: the speed of light is not fast enough).
You could install jacktrip with apt-get, I assume, but the complicated part remains creating a jack application that plays well with Bela, assuming it's possible. You can definitely put something together that communicates with the Bela audio callback via buffers, but you'd really want to avoid that buffering and have Bela be the clock generator. In the first case, you'd probably have a Bela program that operates as a Jack client. In the second case, you'd probably want to write a Jack driver (audio backend) that uses Bela. I haven't worked with the jack API before, so it'd be good to find some good starting point example for each case ...
