Apple Watch with corporate iPhone?

Verizon business plans to not allow dual billing, so if your company iPhone is with Verizon you cannot add the Apple Watch. AT&T offers dual billing, but your company has to agree to it. That would allow you to pay for the Apple Watch sharing your iPhone's phone number. I do not know about T-Mobile corporate plans.

If you are blocked from adding your Apple Watch to your corporate iPhone, then you have 3 options.

A) stay with the GPS only model, and keep your iPhone nearby.

B) If your iPhone supports Dual SIM (a physical SIM and an eSIM), then you can get an eSIM phone number (paying full price) and share your eSIM iPhone number with your Apple Watch.

C) You can let your Apple Watch pretend it belongs to a dependent Child (which has dependent child limitations), using the Apple Watch Family Plan (Google It). NOTE: Your Wife would have complete control over your Apple Watch, and there are some services you cannot use because they depend on having access to personal iPhone information which a Dependent Child would not be normally allowed to access.

You need to buy a watch that works with the service provider she has for her iPhone. The cellular watch's data plan is an add-on to the iPhone plan. Usually $10. If you aren't getting her a cellular model, but the GPS only model, it doesn't matter, that watch doesn't need a plan.

As to the complicated thing you want to do for yourself, no I don't believe that you can do that.

M1 Mac mini, macOS 11.2.3; Watch, series 5 GPS/cellular, watchOS 7.3.2; iPad Pro 2nd Gen, iPadOS 14.4.1; iPad Air 2, iPadOS 14.4.1; iPhone 12 Pro, iOS 14.4.1; TV 4th Gen, tvOS 14.;  HomePods, audioOS 14.4.1 and Airport Express w/ Airplay 2