I've been bumping mine by 5 pounds. I'd look at it more in terms of your max for the exercise, not whether it is a lower or upper body exercise. For instance, I out bench my power clean by about 100 pounds (yes, I suck at the power clean). It wouldn't make any sense if I was bumping my power clean by 10 pounds every week and only bumping my bench by 5, which is what I'd be doing if I treated the power clean as a lower body lift and applied the 10 pound recommendation.
My read of the rationale behind the higher per cycle increases on the lower body exercises vs. the upper body exercises is that most people are going to have higher squat and deadlift maxes than bench and overhead maxes so bumping lower body exercises by 10 pounds and upper body exercises by 5 pounds will roughly give you the same percentage increase for each lift.