Question about fungal amendments to soil

[Mugsie]

I've been reading recently that it benefits the plant to add mycorrhizal fungi to the soil. Have any of you found this to be true? Is it needed? If so, what brand do you recommend. Amazon has multiple brands listed so is one better than another? Also, do you add granular fertilizer to the pot as well? I thought orchids needed a fertilizer specifically formulated for orchids as they were unable to utilize the nitrogen in its regular form. Am I correct in this assumption?
Thanks all.