The federal government has allocated to states, and pretty much left it up to the states how to allocate internally. With some vague sort of guidelines.
Most states seem to be deciding to prioritize healthcare workers (especially those taking care of covid patients) either entirely or among other groups. So the way you do that is delivering to hospitals makes sense. CA presumably allocated a certain amount to Stanford Medicine, as a large hospital system. I don't know how CA decided what hospitals to give to in what amounts, but it certainly wouldn't shock me if political influence were part of it, why wouldn't it be, what sort of guidelines or transparency is there to stop it? There is not really any written procedure for how to decide which hospitals to get how much in most states, it's just... happening.
Then Stanford was clearly left entirely on their own to decide how to allocate internally.
This is far too important and too politically fraught (political in terms of POWER, in terms of distributing a resource for which demand far exceeds supply for something that can literally be life-and-death) -- to have left it up for everyone to just make up their own prioritization rules and medical ethics determinations on the fly, in a hetereogenous way. It means people will make terrible mistakes, and the powerful will take advantage to have their needs prioritized.
It is ridiculous there aren't much more clear/specific guidelines, and in some cases enforceable policies/regulations, from the federal government. It's like nobody's driving the bus here