Teka was one of the Anethans who had been taken by the Skonnans to be a sacrifice for the Nimon. She and her fellow prisoner, Seth, whom she hero-worshipped, helped the Fourth Doctor and Romana defeat the Nimon, and together they returned to Aneth. (DW: The Horns of Nimon)
If a medium is not mentioned, then this incarnation did not have companions who were original to that medium; it does not mean that this Doctor failed to appear in that medium.
