Here's a solution I recently tested and discovered to be effective! I've mentioned it as a *idea* since I believe SONOS might provide a similar solution, unless (of course) licencing constraints prevent them from doing so without Apple's approval. (I'm not sure... just speculating here.)
On your Mac, this software solution instals a "airplay" driver that points to one of your Sonos units. Once installed, you may utilise it in three simple steps.
Step 1) Launch a terminal (command prompt) and enter airsonos. This activates the driver.
Do not end the session. It is acceptable to minimise the window.
Step 2) Select the Sonos as the sound output in the Mac's "System Preferences...", "Sound" menu. Now, play some music on your Mac and increase the volume such that the sound emanates from your Sonos" rather than your Mac. There are no wires. There is no fuss.
Step 3) Smile from ear to ear as any and all Mac sound wirelessly streams to your Sonos!