Tom Buchanan is certainly an egoist with questionable morals and we can also read his character as being symbolic of a larger demographic, to some extent, but not representative of a whole class. It is worth pointing out that Tom is presented as being the least intelligent character in the novel.
Tom's ego and his short-comings are the most prominent part of his character, so we might have to hold off from the conclusion that he embodies an outward, positive bigotry in regards to women and suggest instead that Tom represents the generally shared insularity and selfishness of his social group.
His relationship to Myrtle does emphasize the disparity of their situations, underlining his power and offering flattery to his ego. However, the same can be said of Myrtle and what she enjoys as a result of their relationship.
Tom's tendencies toward bigotry seem to be race related to a greater extent than they are gender oriented, yet these tendencies are not shared by the other characters who also occupy the same "upper class" in the society of the novel.