I disagree...not two tiered but multi-tiered.
Big companies will have corporate policy plus individual bosses within the organization will flex some. Small companies will go with the personal feelings of the boss tempered by his relationship with the employee. It also depends on what kind of job the woman is expected(paid) to do. There's probably half as many tiers as there are people affected.
So I'm saying there is no standard.
But ladies, if you wish to feed or pump, probably the best way to get permission from the boss is get him involved. Let him in on the action....I mean program....yes that's it, the plan... make him part of the plan.
Hell, it could even be a team building exercise.