Apple watch

If you want to use the cellular service on the Watch then you must have cellular services on the iPhone as they are both connected. The Watch will use the same number as your iPhone even though it will be given a second one by the phone company.

So no iPhone cellular plan = no Watch cellular plan.

Wifi only

You can have iPhone cellular plan and no Watch cellular plan but not the other way around.

No you need to have a valid cellular plan on your iPhone to get the cellular plan on your Watch. They go hand in hand. As the Watch uses your iPhone number

The Watch is paired to the iPhone. So yes he will get all your emails and texts and calls when close by or on your cellular. He can also text and call from the Watch using your number of your iPhone

You mean cellular service?

No it doesn't.

Though you'll only be limited to you iPhones Wifi.

No only one number for iPhone and watch currently

cabone wrote:

Can I only allow certain numbers to call his watch

No.

The phone and the watch are designed to be used by one person, not two.