You won't find what you're looking for because that information doesn't exist. Planting of fruit trees is done according to how they're going to be trained and pruned, so, if you were growing trees cordon style, then you'd plant much closer together. If you're not intending to train or regularly prune your trees, then your guide to planting distance, one from the other, is down to the eventual crown width of each tree. Since you've said they're semi dwarf, I've managed to establish that Black York will have a spread of 10-12 feet and has a rounded crown, but can't find a spread mentioned for Rynbrandt. That information may or may not be on the label supplied with the tree, but if its not, then you'll have to just make sure you plant it an absolute minimum of 15 to 20 feet away from the Black York, no closer.
I note also that neither of these trees is self fertile, and needs other trees for fertilization purposes - Rynbrant appears to be listed as early to mid in bloom terms, whereas Black York is listed as mid season bloom. Hopefully, they'll be in flower at the same time for at least some of the bloom time, though maybe you already have other trees that will help with this.
It's fine to plant in the same area as apple trees - but again, not too close, considering the size of the apple tree and the size of the cherry tree's crown. You should leave probably 15-20 feet between them, but it depends on the size of your apple tree, and try to make sure one tree doesn't cast too much shade on any of the others.