Hmm interesting - I've booked my mother-in-law a stay while logged into my profile, and got the VIP discount booster rate from my status. Throughout the booking process it said VIP breakfast, and if I view the reservation from my profile, it still says VIP breakfast etc. But I've also created a brand new Radisson Rewards account for her, and if I view the reservation from her profile, it doesn't mention VIP benefits or breakfast, but still has the same discount booster rate.

So I'm assuming worst-case she'll get the discounted rate but no breakfast, and might get lucky with a room upgrade/free breakfast. I'll try to remember to report back!