I doubt it, but the best way to find out is to bring the bike down to your local dealer and pull a Nomad/Voyager passenger seat off a bike and see if it fits on yours.
If you want the passenger seat modified either find a local motorcycle seat upholsterer or I can give you the contact information of my seat guy who does great work. You would have to mail the seat to him with a discription of what you want and he will make a seat your wife will hopefully like.
If your wife only rides with you periodically, you can just get one of those temporary items that drape over the seat to add comfort.
2010 Vulcan Voyager 1700 ABS, 2007 Vulcan Mean Streak 1600
2012 Concours 1400, 2011 Versys 650, 2012 KLX250S
see my garage for list of accessories