to bus = to transport/carry/take by bus
"Bussing" often refers to the following. There are areas in which large numbers of minority children live. It is believed by some that it would better if they attended schools with a better mix of races and cultures. This is achieved by taking by bus a percentage of them from their neighborhoods to schools in other areas. I do not know if it is still done in the USA.
Around 1985 a friend was upset because his daughter was taken from their neighborhood to a distant school because it was believed the school had an overly large population of Hispanics. My friend complained about the bussing. His daughter was not Hispanic, she was Brazilian. (I do not recall if Bianca was born in Rio or in California.) I do not know how the complaint ended.