The timeline seems off... I remember Pacmania in the arcade, but that would have been during the days of Sega Genesis/ Megadrive, not the VIC. Very strange to me.
Unlicensed? You mean they didn't have a license to make a Pac-Man clone? If the name "Pacmania" was possible to register as a trademark, it rather should've been Namco applying for a license to reuse it later. But probably since they held the rights to Pac-Man, as an extention to the trademark they had rights to names such as Pacmania, Pacmanland, Pacmanga, Pacmanoids and so on.