not "中文什麼說？", but "中文怎麼說？"

Chinese won't care too much about it...麵包店is to describe stores selling bread,蛋糕店is to describe stores selling cakes,and烘焙坊is to describe stores cooking things like bread,cakes etc. 麵包店and 蛋糕店 is a little limited,but烘焙坊 is much more broader.if you want to get more detailed,just contact me.

Generally speaking, Chinese don't know much about western bakery, so those names are only the signs to let you know that they sell 'sort of' cake or bread or Croissant or Battenberg or cookie or whatever. So there is no ONE CORRECT way to say it. If you are opening a bakery, you can choose whichever name you like, and put a picture to let people know what it's about. 

非常感謝！Indeed this is for a business purpose and your insight about this is word really useful and interesting and clear. Thanks a lot!!! :-D