The problem with both of your mixes is not the components. The problem is you did not sift the mix to remove dusty, air void clogging fines. An ideal bonsai mix all the particles are roughly the same size. No fines, no coarse chunks. The exact opposite of the way concrete is made.
All mixes are dramatically improved by removing the fine particles. If you don't have a set of bonsai sieves, get a set.
It's always a good idea to sift the very small particles out of your soil before potting. This helps aeration by keeping your soil cleaner and reducing clogging around the drain holes. You may also want to sift unnecessarily large particles out as well, thus creating fairly uniform particle size...
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Until your new set of sieves shows up, use a piece of window screen. Sift the dry mix components before mixing. Anything that goes through the window screen is too fine to be in a bonsai pot. Mix your dry components together and then sift again. You really need to get rid of the fines.
I'm pretty sure there is nothing "wrong" with the Schultz Orchid mix, it just has too much in the way of fines. Sift it, and what stays on top of a piece of window screen will be fine as a bonsai mix component.
Potting soil. This is a big mistake as nearly 100% of potting soil is fines. This all goes to plugging up the pores in your potting mix. This is the one component to leave out of your mix.
Hope this helps.