Can bacteria from a UTI travel?

Yes. If by travel you mean can the bacteria travel from their current location, bladder, where they are causing a uti. Not uncommonly, if untreated, UTI causing bacteria can travel up the ureter to the kidney causing a more serious infection called pyelonephritis. Patients with pyelo will have fever and flank pain. In this care bacteria can rarely travel to the blood or cause a local abscess.
Yes. Bacteria can spread in body through natural channels and by invading the blood stream.