i don't know what constitutes a "bonded" pair. i added one to my dt and a few months later, added another. they paired up immediately and are rarely seen apart. there is a definite color difference in them. i suspect i have 1 male and 1 female but i got them several months apart. love these fish, great personalities and if i am anywhere near the tank, they are front and center.
<a href="http://s6.photobucket.com/user/Ninapearl/media/TANK/2hawks_zps1e1c1b14.jpg.html" target="_blank"><img src="http://i6.photobucket.com/albums/y203/Ninapearl/TANK/2hawks_zps1e1c1b14.jpg" border="0" alt=" photo 2hawks_zps1e1c1b14.jpg"/></a>