The deal was ratified by a 212-69 vote Thursday. It includes 1 percent raises for the highest-paid bus drivers and mechanics.
The transit agency and Teamsters Local 104 agreed to a $773,000 package that includes raising pay for top drivers from $18.53 to $18.72 within the next two years.
Those drivers along with the highest-paid mechanics hadn't received raises since 2010.
The Arizona Daily Star says pay for top mechanics will increase from $21.94 to $22.16 in the upcoming two years.
Sun Tran and the union reached a tentative agreement Tuesday, allowing drivers to work under the terms of the old contract while they voted on the new one. The two sides had been negotiating for six weeks.