Apparently it will according to this link…

https://www.reddit.com/r/sonos/comments/mupgl0/roam_charging_pad_work_with_other_devices/

...but I think it’s only 5w power-output, which is perhaps fine for the Roam, but maybe a little slow for fast-charging devices. So I personally would buy a fast-charger Qi pad instead for my phone, but it’s each to their own, I guess.

Ken is correct, you can use the Sonos wireless charger to charge other devices. I occasionally use mine to top up my phone when I’m not using it