Just to note the US Department of Agriculture cited about 1.8 acres to satisfy modern dietary needs for the average Freedom Lover, so we'll call that 1.8 to make a modern chubby.
I cut that down to .5 on account of it being the future and any kind of super efficiency there might be.
Like I said, you can manipulate the figures however you want. Even if you can feed 10 people off of one acre of land you end up with structures of mind boggling mass.
If you cut those numbers down to 1000 rather than 100000000 the size becomes far more reasonable for what we're to expect from what's in front of us.
1 km² = 247 acres * 2 people = 494 people.
Now lets assume that a few of those people are fat and make it 500 people to keep everything simple.
1000 / 500 = 2 km² to feed those one hundred Zoners, assorted guests and overflow to sell to passers through, storing excess each season. Bending/etc the biodome's surface further reduces overall impact of the surface area required.
Even still that structure, and the space required to service it, is beyond gargantuan.
Maybe later I'll do some math on how many tonnes of earth would need to be moved, how many trillions of gallons of water and the space required to simply store the food etc.