This is a wide spread Brazilian species. When this happens it is common that ecotypes appear and C. bicolor has a few (minasgeraisensis, brasiliensis, paulista, canastrensis). In general these ecotypes show some variation in the color and or the lip size. A well established characteristic of this species is the lip without side lobes, as can be seen in the photo that follows. I many times see plants labeled C. bicolor and a quick look at the flower reveals small side lobes partially involving the column. All these flowers resembling C. bicolor, but having small side lobes by the side of the column, like the one I'm posting bellow, are hybrids, not pure Cattleya bicolor.
Cattleya bicolor (note the lip without side lobes)
Cattleya bicolor Lindl. - var. brasiliensis on Flickr - Photo Sharing!
Below: hybrid Cattleya involving C. bicolor