"Bards make journeys."
Translation:Vates itinera faciunt.
It's more iter for the nominative, accusative, and vocative singular and then the rest of the cases are formed off the stem itiner-. These kinds of odd changes between some of the form I find is quite common in the third declension.
Based on Wiktionary (take with a grain of salt) it is related to it (maybe not directly), and the nominative/accusative/vocative vs other cases is a conflation of different stems.