The Vista school board is postponing plans for a $274 million bond measure that would have upgraded school facilities.The bond measure would have paid to renovate aging infrastructure, replace portable classrooms with permanent ones and enhance instructional technology. It was slated for the November ballot. Instead the district aims to place the bond measure on the ballot in 2018, said Donna Caperton, assistant superintendent for business services. She said the district plans to seek more community input and prioritize projects covered by the bond.