I noted that if you do a google search on this topic, it's mostly rants about misconceptions ("RJ made men stronger in the OP and that's wrong" ) and genuine points that RJ had peculiar notions about women's behaviour. Or, of course, that he was too old-fashioned and gender-conforming and probably licking his lips when writing about nudity. Oh, and no gay characters so he must have been homophobic, too.
The starting point of gender in WoT has to be the Breaking which damned men forever with the original sin of channeling Saidin. In the AoL, Graendal implies, the genders were considered fully equal. Even the nurturing Talent of Healing, divided post-Breaking to inefficient male and female forms may be quite eavenly shared (Flinn emerging as a superb Healer, for example). It's certainly no coincidence that the most gender-imbalanced society is Far Madding, a community formed by people best insulated from male evil (saidin) and determined to keep it out.
After FM, I think the second place for the most sexist society goes to Malkier and Shienar. These are cultures where men are owned by women from birth (boys are neuters that are allowed to enter the woman-world of Shienari noblewomen's living corridors) to adulthood (obeying your Malkieri carneira, first lover) and finally death (buried naked in earth as the mother's last embrace). Nynaeve and Lan both benefitted enormously from the Sea Folk rule arising from their chain of command that the publicly dominating partner must defer in private. It kept Lan from sinking into his old habits and released Nynaeve from her 2Rivers mentality. She learned to love men (so to speak) as opposed to Elayne who from the start was curious and caring, not patronizing, towards Rand.
What about the Seanchan? The military is open to women. Perrin was dealing with a high-ranking female civil servant whose power was not inherited (she wasn't of the Blood). There's no benefit to being a channeler, female channelers are awarded a lifetime of slavery, male channelers killed. Perhaps that's why they appear more balanced despite being the descendants of the main continent.
Your ideas? How did RJ succeed in creating a matriarchal society? Was his portrayal of women as violent, bitchy and despotically controlling of men (e.g. Egwene's mother openly admitting her deft manipulation of her husband) ignorance and sexism or a reversal of modern-day patriarchy with an equally repressive matriarchy? One more way to portray the damaging consequences of the Breaking rendering men and women apart and keeping them from working together?