Some things to consider in terms of protein requirements.
Generally speaking, they increase in accordance to the volume of exercise done (protein is oxidized as fuel), the damage done to the skeletal muscle (protein is required for repair), and the stimulus of the type of exercise (resistance training increases muscle mass, which requires protein), and the amount of calories in the diets, especially from carbohydrate (carbs spare protein).
Definitely both PL and BB require higher levels of protein than if you are not training, but, depending on the situation, BB may require more.
BB'ers generally do a higher volume of exercise than PL'ers. More sets, more reps, plus cardio. PL'ers are more interested in optimizing strength gains, which requires higher loads and therefore fewer sets.
BB'ers often intentionally "damage" skeletal muscle to stimulate growth. We relish DOMS. PL'ers often do, too, but this is of less concern. Some PL'ers often train with 5 or fewer sets for a given lift once a week or less frequently. This will incur less damage than 15 sets every 5 days, even if those are not taken to failure.
BB'ers are often (LOL ) trying to increase muscle mass. A bigger BB'er will look better. Exception to this might be those who strategize to stay in a given wt. class b/c the competition will not be as tough. PL'ers are often inteterested in optimizing strength at a given weight. This might entail maintaining bodyweight for years, even when they could easily balloon up to higher weights, but without increasing strength "proportionately" (obviously not a linear rel. between BW and strength).
BB'ers are often dieting, which elevates protein needs to offset increased rates of catabolism. PL'ers are less likely to do so, at least to the drastic levels that BB'ers do (it would hamper strength too much).
So, I'd generally say that BB'ers, *on average*, would require slightly more protein than PL'ers, but there certainly could be situations when a certain PL'er would need more protein than a BB'er...
I liken a powerlifter trying to get as strong as possible, to a bodybuilder trying to get as big as possible. Unless the powerlifter is cutting calories in an attempt to make a weight class, I liken the diet of a powerlifter to that of a bulking bodybuilder. Lifting heavy loads still causes stress and tissue damage that your body has to repair. The type of training you perform in the gym is more likely to determine if you get stronger or bigger, rather than the diet. All this taken into consideration, if you want to help your body repair the damaged muscle tissue, you will consume a larger amount of protein than an average Joe, and this applies to bbs and pls alike. Now, endurance athletes and "cutting phases" are different stories. But that's a tale for another time.