My gals do not like pellets so they are on organic coarse grain layer mix which is not bantam specific. If they did like pellets, I would buy them bantam sized ones or ensure that the larger ones are broken up a bit.
When I purchase oyster shell for them, I buy the bantam sized.
Because mine fly like bricks their roosts are lower than what you would probably have for a standard.
Because they are smaller, I am careful with regards possible predators as things which do not normally bother standards may be a threat to bantams, especially small ones; eg. Crows are a problem in my area.
As with anything chicken, there are always exceptions to the rule but in general, bantams have the same requirements as standards, just in proportion to their size. They are cared for and raised pretty much the same.
I have Belgian d'Uccle bantams and a mixed flock of standard birds, and they all do fine on the same ration and environment. Currently they are on Flock Raiser crumble, but when every one of this year's babies is grown, back to Layena pellets. I don't have more delicate birds like Silkies or Seramas. Hawks definitely are more able to take the bantams, especially youngsters, before tackling a big bird. Other predators have been happy to get anyone. I do have a Ft. Knox coop! My bantams roost eight feet up in the rafters! Mary
My bantams eat pellets and whole corn, so I have a different experience with food, bantams go broody quite often. Bantams get along with each other better, they make a lot of noise but I haven't ever had them injure each other, except for roosters occasionally going at it. And the rooster to hen ratio is a bit different, less hens per rooster.