This is quite a difficult question to answer as wireless/WiFi environments around a Home can vary so much, but a reasonable proximation to replicate the HT Ad-Hoc 5Ghz ‘bonded’ link, might be to place an available Sonos speaker in the chosen locations and a wireless access point near to the location of the Soundbar and see what SNR reading shows in the Sonos App, over a 5Ghz only connection. You ideally need 45dB, or higher. See this link:
https://support.sonos.com/en-us/article/selecting-a-location-for-your-sonos-speakers
See this support link below aswell, which shows where to locate the SNR reading in the Sonos App.
https://support.sonos.com/en-us/article/understanding-the-network-details-section-in-the-sonos-app
Personally speaking though, I would just try the setup and see if it works, particularly if you opt to buy the 2 x Era 100s direct from Sonos, within the terms of their 45-day money-back guarantee, that’s if the speakers do not work for you at the chosen locations. See this link:
https://www.sonos.com/en-us/legal/terms#legal-terms-sale-warranty