Two iphones, only want to carry one

Why don't you just talk to your employer about it. They may agree to just reimburse you for part of the cost of your cellular plan if you use your own phone and service instead of theirs... You could use a service like Google Voice to get a second number for use as a 'business' line so you can receive calls and messages on your personal phone without having to give out your personal phone number.

Contact the carrier used on the work phone and see if they support forwarding SMS. For iMessage, you would have to add the phone number for the work phone to the personal phone. If they are not on the same carrier, then you probably cannot get SMS forwarded. SMS is a carrier function, and they are the ones that determine handling them.

Let's assume you don't really want constructive suggestions since your immediate reaction to the first one you get is to attack the person trying to help you.