Can tinea versicolor and recurting yeast infections be related? can they cause one another?

Possibly: They are both fungal infections and suggest that the immune system isn't functioning as well as it should. The biggest cause of immune dysfunction in our society is stress, which can reduce your th1 immunity (allowing more infections) and which also results in an increase in th2 immunity (causing more allergies). Meditate, eat well, exercise.

Vaginal yeast infec?: I'm going to assume the question refers to vaginal yeast infections rather than yeast infections of the skin, like yeast folliculitis. Tinea versicolor is caused by a different fungus than the one that usually causes vaginal yeast infections. I don't think they're related, however, it's possible that your immune system doesn't fight off fungal infections very well.