Single Supply Op Amp Bypass Caps
No, you don't put a bypass cap on a pin that is already connected to ground.  The bypass cap should be between the two power pins of the opamp, physically as close as possible.

It would be good for the bypass cap to have its own connection to the grounded power pin.  In other words, don't run the bypass cap current accross the ground plane.  Keep the high frequency currents thru the bypass cap off the ground plane in as small a loop as possible, then connect one point of that loop by the negative supply pin to ground.