Davenport Iowa Thruway Connection

Amtrak's system map lists Davenport, Iowa as the terminus of Thruway Connection Route, and it is available to select as a station when making reservations. However, I cannot book any Amtrak travel that has Davenport as either the departure or arrival station. I've booked travel that included a thruway bus before with other destinations. What's going on here? How do I book Thruway bus service in Davenport? What's the best non-car option to get from Davenport to the Amtrak rail network?

Related question, when, if ever, are the Quad Cities getting Amtrak train service to Chicago? That route would change my life.