signal propagates in bending transmission line (unequal length between signal path and return path)
However, the outer transmission line is longer than the inner transmission line because of the bend, thus, V- travels a longer distance than V+, so should I see a the two signals appears on the oscilloscope in different time with V+ arrives at oscilloscope earlier?


Yes, this can happen.

It also causes differential-to-common-mode conversion which can be bad for EMC.

But it's normally only a significant problem for signal frequencies above 2 GHz or so.

Reducing this effect is why you'll sometimes see a differential pair with a serpentine in one trace but not the other: 



(image source)