Firstly the hyphae secrete enzymes onto a food source, which break down polymers into monomer units, which are then absorbed into the mycelium by processes of active transport and facilitated diffusion. In both terrestrial and aquatic ecosystems, mycelium plays a vital role in the decay of plant matter, and it contributes to the organic component of soil releasing CO2 back into the atmosphere as it grows. The mycelium of mycorrhizal fungi acts in symbiosis with a plant whose roots it has colonised, and acts as a conduit for water and nutrients such a phosphorus to the plant, receiving in return sugars from the plant which it produces through photosynthesis [3]. Some resistance is conferred also against plant pathogens by mycelium, and which also provides a food-source for many soil invertebrates - beetles and worms, etc.
So the above is in a symbiotic relationship with plants so growing it with your marijuana would be beneficial.