The Salt Flats were there in name well before the bike, in fact the bike that broke a speed record at Bonneville was a Triumph Thunderbird which was renamed after the record as the Bonneville.
Different versions of this but the Bonneville Salt Flats was there long before cars and bikes.
----------------
Ride on !
p.s. If you want to know which came first between the Ford Thunderbird and the Triumph Thunderbird, then you will be happy to know it was the bike by a long way !