This year's winter bonus was smaller than usual.
The bonus payment date varies by company.
A more general sense of a reward or prize given for merit or achievement. Less common than the bonus sense; often used in formal or written contexts.
A reward was presented to the person of merit.
The company paid its employees a summer bonus.
Performance was good this year, so we got a big bonus.
The winter bonus is scheduled to be paid in December.
賞金 refers specifically to prize money given for winning a contest or competition, whereas 賞与 in its reward sense covers any formal prize or recognition for merit.
Compound of 賞 (praise, reward) and 与 (give, bestow). The reading is on'yomi.