I have two identical bass tracks that I recorded.  I want to bounce them to one track to eq and such.
When I choose the two tracks and do the bounce to track, the new track has a flat audio line with no sound.
Any ideas?

Try routing the tracks through a bus and bounce the bus (or solo the tracks and bounce the mix). Or don't bother with bouncing the tracks, just work with the bus.

I wouldn't bounce them to one track. If they are 100% identical (=copies) theres no use to have the double anyway, it does not add anything to the sound.
If they are double tracked (=with minor differences) you might bump into phase problems which you can not adress anymore if the tracks are bounced to one. The same goes in the case you create minor differences by nudging or using distortion or EQ.
 
ADDED LATER:I have never created purposely a 100% phase cancellation, so I don't know how it's shown on the track. Maybe that's what you are experiencing? That means opposite phases of sound wave cancel eachother causing silence.

Unlikely to achieve total phase cancellation, but if the Track numbers are selected for the bounce, and the waveform panel selection area is outside of those Tracks' actual parts, a flatline will result.

If all you're trying to do is get the same clips into one track you can just drag and drop them into the new track.
If you press Shift when releasing the left mouse button the clip will drop into the exact start time as you pulled it from.  If you want to copy the clip into a new track just also hold CRTL at the same time.  If the clips overlap then you can set up track layers to view the clips separately (ask if you're unsure how to do that).