What if the iMac or Mini is connected by Ethernet and not wi-fi? Will it still work? And the iPhone doe need to run iOS 16, correct?

On a Mac since 1984.
Currently: 24" M1 iMac, M2 Pro Mac mini with 27" BenQ monitor, M2 Macbook Air, MacOS 14.x; iPhones, iPods (yes, still) and iPads.