Southwest Airlines Community

If my work books a flight on Southwest Airlines on my behalf (using my rapid rewards number) to and from a conference, would I be able to change the return flight to a later (more expensive) date and pay the fare difference myself on my own personal card? Would my work be notified of this change? Also, I am hoping that I have the companion pass from the credit card promotion by the time this trip comes around. If I have the companion pass, could I add my companion to just the return flight as well? I want to be extra sure before I make a decision of which flights to book! Second guessing myself ... View more