Premium, prize, award, reward, meed, guerdon, bounty, bonus are comparable when they mean something which is bestowed upon a person as a recompense for cooperation, greater effort, superior merit, or supremacy in competition.
Premium is applied usually to something extra or additional that serves as an incentive to buy, sell, loan, compete, or strive.
Prize is applied to something which is striven for or, sometimes, which may be won by chance; it is bestowed upon the winner in a contest or competition or in a lottery.
In extended use prize commonly implies effort, struggle, and uncertainty in the seeking and often imputes value or worth to what is sought or competed for.
Award implies both a decision of judges and a bestowal of a prize or an honor; it is therefore often preferred to prize when the recipients have not been competitors in the strict sense but have in their work or performances fulfilled the conditions required by those who offer prizes.
Award is also applicable to the act of awarding a prize or to the decision in a particular competition.
Reward strongly involves the idea of recompense for something good or meritorious or ironically for something evil; it may be used in reference to a prize or premium only when that has been earned (as by effort or sacrifice); thus, a winner of a prize for the best novel of the year may feel that he has been given a reward for intense effort; a reward is offered for the return of a lost article.
Meed and guerdon are close synonyms of reward, often employed without distinction, but the former tends to suggest a reward recognizing merit and proportioned to it, and the latter a prize or honor conferred as a reward.
Bounty and bonus are applicable chiefly to a sum of money or its equivalent given as a premium or reward.
Bounty is usually applied to a premium promised by a government or governmental agency as an inducement to some act (as enlistment in the army or navy, emigration to a distant colony, or destruction of noxious animals or pests) or as a subsidy to industry.
Bonus, in contrast, is usually applied to something given over and above what is regularly received or due, either as a reward or encouragement or as a distribution of surplus.