I usually use about the same width grip when benching vs rowing, but I change width quite a bit as a kind of muscle confusion technique and to make sure I'm working muscle groups from different angles. By going wider than standard width you can hit a little more lat flare and rear delts on rows. closer grip you can hit the lower lats and traps and also work thickness a little better. all depends on what you're looking for out of the exercise, i try to mix up the way I do almost all exercises in the gym. I know it was a slightly vague answer, but that's my opinion - hope this helps