只能用for的情况 be beneficial for somebody to do sth
其他的for/to sb/sth 随便用,都是没错的
不过to是标准搭配
例句
I think it would be beneficial for each committee member to have a copy of the report.
Some alternative treatments may prove highly beneficial.
The arrangement was mutually beneficial.Lowering salt intake has a beneficial effect on blood pressure.
Relaxation classes can be beneficial to people of all ages.
The relationship was to prove mutually beneficial over the years.We only fund projects we consider to be socially beneficial.
Work experience is usually highly beneficial for students.