Hi VirtualSMF,
welcome to our forum.
You are right, RuneAudio not use PulseAudio and never will, but you can use AirPlay right now, to achieve your needs.
In the upcoming realease v0.3,
AirPlay support has been enhanced.
You could also use DLNA protocol, but we will introduce it later, in release v0.4.
Ciao.
Simone