Starting from today (1 May):
5.1: From 192 kbps (good) up to 640 kbps (great/perceptually transparent)
Dolby Atmos: From 448 kbps up to 768 kbps (Dolby Atmos is available for members subscribed to the Premium plan):
https://media.netflix.com/en/company-blog/bringing-studio-quality-sound-to-netflix
5.1: From 192 kbps (good) up to 640 kbps (great/perceptually transparent)
Dolby Atmos: From 448 kbps up to 768 kbps (Dolby Atmos is available for members subscribed to the Premium plan):
https://media.netflix.com/en/company-blog/bringing-studio-quality-sound-to-netflix