I'm not so sure that the Vistana sales reps are correct about that. I thought that the Marriott Bonvoy Choice Benefits were earned based on elite night credits. Bonvoy members get one Choice Benefit at 50 nights and a second Choice Benefit at 75 nights.
So because you earn your Bonvoy status based on hotel stays related to your business travel, you would be eligible. But I'm not so sure that you wife will get the same benefit because her Titanium status is based on her timeshare ownership rather than elite night stays. She might have to earn her own 50 or 75 Bonvoy elite night credits (from some combination of Bonvoy credit cards, timeshare stays at Marriott or Vistana resorts, and hotel stays) in order to earn the Choice Benefits.
If I'm wrong about this, I'm sure someone will quickly correct me.