Security on separate ssids? Trying to isolate sonos

hi, i have an older nighthawk X8 and I am trying to connect a new sonos system. Problem is this is for a property that we rent out on airbnb. I want the sonos on a guest network.  I dont want guests to access any of my other smarthome/IoT devices. 
But, devices on a guest network cant view each other. If I allow that they will also have access to my LAN.

Potential solution… rename one of the ssids on the main network as sonosaccess and treat that as a guest network. Will this work? i am assuming they wont be able to access anything else on my main network if it has a different ssid.

any thoughts on this? Or other ideas?

i was about to upgrade to a mesh system but abandoned that when I realized it wouldn’t let me isolate sonos while mynokd netgear systen might….Thanks