Mycorrhizae help

From what I understand the fungi vastly improves the Health of a plant by transferring things to the plants roots it can't absorb as easily.
so by mixing soil worm castings and bat guano?
Also do I mix bat guano directly into the soil for veg then add a top layer of guano for bud?

Mycorrhizal fungi make phosphorus more available to plants, but your question isn't clear. If you're asking whether the phosphorus in the guano will be more readily available to the plant with myco's added then the answer is probably. Top dressing with guano is also common, but I can't tell you how effective that is compared to having it in the mix. Probably less.

Hmm I apologize for the confusion this is all new to me. I guess what I am asking is bat guano and worm castings enough to inoculate the fungus or is bone meal and other ingredients necessary?

as for the top layer question if I put guano high in N in the soil would I come back and add a P heavy guano to a top layer for budding?

the fungi are sold in packages...you can find them at hydro stores, or online. I would recommend "Myco Grow" by Fungi Perfecti (paul stamets' company..if that rings a bell at all) Myco Grow Soluble.

As for the guano, I would skip it altogether for various reasons. Have you considered kelp or alfalfa meal? What about crab meal? neem is another tool I would recommend getting acquainted with, both in the liquid (neem oil) and solid form (neem cake/meal).

is there a reason you are leaning towards guano?