Rebecca Rubin Film and Media ReporterSandra Bullock and Channing Tatum’s screwball romantic comedy “The Lost City” collected $31 million at North American theaters over the weekend, a promising sign that Netflix hasn’t completely seized on the meet-cute market.Of course, Paramount, which is behind “The Lost City,” did not rely only on positive reviews — or the tease of Tatum’s bare behind — to fuel ticket sales. The on-screen chemistry between Bullock and Tatum, who were inescapable on social media, billboards and in trailers while promoting the film, were key in getting audiences to cinemas.