From what I read it doesn't effect us patients. But if you purchase your medicine from a Collective expect to pay more due to tax's that the state, county, and city will impose. Also the extra cost of license's, testing, other things they are requiring will make the cost go up even that much more. Also all current Collectives will be phased out after all the licenses are issued. So if the place you go to now doesn't get approved for a license to dispense they will close. It makes deliveries OK too.
There is no state tax aside from normal sales tax. But yes, local municipalities can impose their own taxes. The cost of licenses will be insignificant however all product will go through distributors from the alcohol industry who will impose a fee of 5% of the wholesale cost. The lab testing fees will be significant and will be paid for by growers/manufacturers.
Dispensaries, growers, manufacturers will no longer be obligated to run under a collective or cooperative model, they can be LLC's or even publicly traded companies.
These laws give local municipalities mandates to either permit or ban medical cannabis businesses. So expect a ton of local ordinances to be authored in the next 2 years. The other side to this is that if a state wide ballot initiative passes it can eliminate the undesirable parts of this law so they never actually go into effect.
It also officially declares cannabis officially an agricultural product in the state of California. I'm not clear on all the implications of that but it should allow for state wide safety standards to be set.