I think on both counts you are on the wrong side of the Ts+Cs

Where there is a lounge (usually a Sheraton but some Westins as well) breakfast in the restaurant is not one of your Platinum Amenity options.

If you had upgraded both rooms with SNAs then both would have Lounge access but as you only upgraded one then you as the Platinum member are occupying the suite and you and anyone else registered to that room are entitled to lounge access. I don't believe that you can reassign your Platinum benefits to another room.
While you can use SNAs to upgrade another person's room I think that only applies if you have upgraded your own room as well with SNAs