Last year on my way to FL. got thumping sound between 25 & 45. FL. shop said I need new tires to replace the new ones I just got. Car is safe to drive. Got back to Yuma, Az. Discount Tire put new tires on to replace the ones I just got from them a month ago. Took to dealer there finding was need new tires. After a little talk they kept it another day. This time they found bad bearings. Not covered under drive train warranty. They called it normal wear at 46K miles.
From my experience a wheel bearing failure is evident at all speeds and will sound like a thump. Next time grab the wheel (tire) with both hands, if there is any looseness the bearing has failed. Yours sounds like a tire failure, belt separation. Check the inside of the tire for bulges, that is a visible indicator of a failure