That is a clear definition for provincials. Motifs and devices that are uncommon to roman coinage might stretch this definition but I see why some cataloguers go both ways on this. Interesting stuff!
Great coin, JBG ... very sweet!! I have a couple of cool Tiberius examples ... ummm, but this raunchy first example has a couple of countermarks blockin' the image of good ol' Tiberius (but still a very cool coin) ... TIBERIUS AE As Tiberius – Caesar 8-14 AD Tiberius – Augustus 14-37 AD Clunia, Spain Diameter: 28 MM Weight: 13.9 GRAMS Obverse: TI CAESAR AVG F AVGVSTVS IMP, laureate head right, countermark of bull rushing right on Tiberius' neck Reverse: L IVL RVF T CALD CON T POMP LON P IVL NEP IIII VIR, Bull facing left, CLVNIA above, countermark of eagle's head on bull SPAIN, Emerita. Tiberius, Æ Dupondius 14-37 AD Diameter: 35 mm Weight: 23.85 grams Obverse: Laureate head left Reverse: City-view seen from aerial perspective: city wall with five T-shaped crenellations fronted by main gate consisting of two arched bays flanked by two multi-story crenellated towers, each with arched window; gate inscribed AVGVSTA/EMERITA and decorated with four T-shaped crenellations
I was reading somewhere that the bull can represent the founding of the colony? Or maybe I'm full of it!
A bull all by itself can signify any of a number of things, depending on the local culture. The coins you are referring to are actually dubbed "founder" types, and show the emperor plowing a field with two oxen, as in this coin from CNG.
... or this example ... PHOENICIA, Berytus. Titus. Æ23 AD 79-81 Diameter: 23 mm Weight: 13.28 grams Obverse: Bare head left Reverse: Founder plowing right with ox and cow