Anathematized - anathemized (error)
anathemised has been seen in print, as well as in students' writing, it is not recorded in the second edition of OED. This is strong evidence that it is not a good word.
Use the traditional anathematised instead. (It derives from the plural, in its original language, of anathema, which is a Greek word for 'a curse', or the expression of a desire that God may abandon the person cursed. (The plural is anathemata.) Nowadays, anathematise has lost much of its religious meaning. It usually means a strong expression of disgust or disagreement, often leading to such proposals as one to expel the offender from the association, club, party, etc., to which both the person offended and the offender belong. The plural of the Greek word, anathemata, means 'a collection of curses'.)
Anathemised is just anathematised with a syllable left out, through either ignorance or laziness. If you want to be considered a good student, try to avoid your tutor's anathemata, by being neither ignorant nor lazy.