I don't know what percent goes to what but here is a list of where the dollars go from the bill text..
https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201720180SB1
(1) The revenues estimated to be available for allocation under the act to local agencies are estimated over the next 10 years to be as follows:
(A) Fifteen billion dollars ($15,000,000,000) to local street and road maintenance.
(B) Seven billion five hundred million dollars ($7,500,000,000) for transit operations and capital.
(C) Two billion dollars ($2,000,000,000) for the local partnership program.
(D) One billion dollars ($1,000,000,000) for the Active Transportation Program.
(E) Eight hundred twenty-five million dollars ($825,000,000) for the regional share of the State Transportation Improvement Program.
(F) Two hundred fifty million dollars ($250,000,000) for local planning grants.
(2) The revenues estimated to be available for allocation under the act to the state are estimated over the next 10 years to be as follows:
(A) Fifteen billion dollars ($15,000,000,000) for state highway maintenance and rehabilitation.
(B) Four billion dollars ($4,000,000,000) for highway bridge and culvert maintenance and rehabilitation.
(C) Three billion dollars ($3,000,000,000) for high priority freight corridors.
(D) Two billion five hundred million dollars ($2,500,000,000) for congested corridor relief.
(E) Eight hundred million dollars ($800,000,000) for parks programs, off-highway vehicle programs, boating programs, and agricultural programs.
(F) Two hundred seventy-five million dollars ($275,000,000) for the interregional share of the State Transportation Improvement Program.
(G) Two hundred fifty million dollars ($250,000,000) for freeway service patrols.
(H) Seventy million dollars ($70,000,000) for transportation research at the University of California and the California State University.
It is the intent of the Legislature that the Department of Transportation meet the following preliminary performance outcomes for additional state highway investments by the end of 2027, in accordance with applicable state and federal standards:
(1) Not less than 98 percent of pavement on the state highway system in good or fair condition.
(2) Not less than 90 percent level of service achieved for maintenance of potholes, spalls, and cracks.
(3) Not less than 90 percent of culverts in good or fair condition.
(4) Not less than 90 percent of the transportation management system units in good condition.
(5) Fix not less than an additional 500 bridges.
(o) Further, it is the intent of the Legislature that the Department of Transportation leverage funding provided by this act for trade corridors and other highly congested travel corridors in order to obtain matching funds from federal and other sources to maximize improvements in the state’s high-priority freight corridors and in the most congested commute corridors.
(p)
Constitutionally protecting the funds raised by this act ensures that these funds are to be used only for transportation purposes necessary to repair roads and bridges, expand the economy, and protect natural resources.
(q) This act advances greenhouse gas reduction objectives and other environmental goals by focusing on “fix-it-first” projects, investments in transit and active transportation, and supporting Senate Bill 375 (Chapter 728, Statutes of 2008) and transportation plans.
I think this is the first bill that does actually force the gov to use the money where they said they would.