Someone on here installed those bed rails that run from the front stake pocket to the back pocket, then built cross rails across them (which would be above a tonneau cover, if it was the rollup kind), then attached Yakima or Thule roof rack type bike holders on the cross rails. I think he made the cross rails out of C-channel that they use for electrical work, see here:
Try doing some thread searching and you might find his pic.
1988 Coleman Sequoia - popup (1987-2007)
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10