Countries and their churches extract rents from their citizens or subjects through various taxes. What taxes were individual Alta Californians required to pay in the Spanish and Mexican periods?
I'm not a historian and have no expertise on California, but overall it seems that neither of these regimes would have had much capacity to impose taxes in Alta California. In theory, according to a Wikipedia article, there were import tarriffs and a tithe or land tax called the diezmo:
Since the government depended on import tariffs (also called Custom duties and ad-valorem taxes) for its income there was virtually no property tax. Under Spanish/Mexican rule, all landowners were expected to the Diezmo, a compulsory tithe to the Catholic Church of one tenth of the fruits of agriculture and animal husbandry, business profits or salaries. Priest salaries and mission expenses were paid out of this money and/or collected goods.
As visitador of New Spain in the 1760s, José de Gálvez made some significant efforts to impose taxes on agricultural production, but only lead preliminary expeditions into Alta California. Here is an article, referring to Sonora and Baja:
Usually the missionaries could convert the indigenous people into a labor force, but the transition to Spanish taxpayer rarely took place. [...] The Mission System created dependency rather than independence, never producing those tax-paying settlers Galvez had desired.
One of the sources cited in the article is a book by Spicer (1962), which describes the long decline of the Spanish mission system from that time through to Mexican independence.
Between 1767 and the 1820's both the village and the rancheria peoples had become accustomed to a growing local autonomy. The mission organ ization in their communities had largely disintegrated, and in the absence of priests, they had themselves begun to manage church affairs.
As for the Mexican period, quoting from Wikipedia, with emphasis added:
Mexico, after independence, was unstable with about 40 changes of government, in the 27 years prior to 1848—an average government duration was 7.9 months. In Alta California, Mexico inherited a large, sparsely settled, poor, backwater province paying little or no net tax revenue to the Mexican state. In addition, Alta California had a declining Mission system as the Mission Indian population in Alta California continued to rapidly decrease.