When you set up a secondary device like a smart watch on your OneNumber plan, it will inherit any bars and services which are applied to your primary device. If you already had bars on your secondary device, these will be overwritten by the bars on your primary one. Any new bars that are added will then be applied to all devices on your account.
Because these bars are set at account level, you can’t have different bars on different devices. So you couldn’t for example, bar your secondary device from being able to make international calls without barring your primary device, too. The only exception to this is the lost and stolen bar, which is only applied on the SIM card that is reported missing.