The most common design guideline that I'm aware of is from the book "Steel Plate Engineering Data" by the Steel Plate Fabricators Association. Inside there are guidelines on many topics including anchor bolts, anchor chairs and anchor saddles.
Is it a vertical cylindrical tank or horizontal bullet type?
If vertical cylindrical, straddle the bolts on the major axes.
If horizontal,
Use steel/steel slide plates if the concrete pedestal or column supports will not take bending load from friction due to saddle movement from vessel thermal expansion, due to ambient temperatures and/or operating temperature.
If expansion frictional load is still too great, use teflon slide plates.
Oversize top slide plate by horizontal expansion distance to keep dirt from accumulating on lower plate.