Well, I can safely say the answer is yes, though maybe not spectacularly so. You'll be hard pressed to find a member of this forum who is into NBE and is not using some sort of hormone altering supplements or dietary elements, but I am one. I've been into massage and use of suction devices for years, but I've never disciplined myself to a rigid ongoing program. However, even casually starting and stopping over a long time I've seen definite and pleasing growth, though not the big showy kind. And it's clearly real breast tissue since I've little fat and the breasts stay the same even if I go a long period without suction.
I've always been very slender and muscle-less and before I started doing suction my chest and nipples were dead flat. I now have permanently perky nipples and and somewhat bouncy breasts that nicely fill at least an AA bralette, anyway. I suspect that if I had been doing a steadfast suction program of a couple of hours a day for several years I would probably have much more visible breast development. However, I'm sure the best way to grow breasts in the most feminine shape would be to combine suction with hormone modification. And, of course, that's by far the quickest way. For me that was not a good choice, though, so I've only gone with suction work.