I'm going to recant on my original post. On second viewing, I heard Carol Marcus say "advanced warp drive." So, no direct mention of transwarp. But one could make the connection that "advanced" warp = "trans"warp.
She didn't say anything like that. Her exact words were: "He's been designing a ship with Mark-Four capabilities, including--" but she never finishes because the Vengeance shows up right about them.
She probably means "Mark Four WARP capabilities," which might imply a "transwarp propulsion units, Mark-IV." Given that the older ships in the fleet might have been retrofitted to the Mk-II (Mk-I being a prototype that entered service WAY earlier than expected) Enterprise would be the Mk-III.