Great question. Would love to hear other suggestions. Consulted many resources, but not easily finding this in an education context.
Portuguese-PT reference below in PDF discusses a grading/ranking rubric (item 9, Critério de análise das candidaturas), so is closest to your context:
"A atribuição da majoração tem como limite a pontuação máxima de 100 pontos (p. ex., se antes de majorada a candidatura tiver 90 pontos, a pontuação final após majoração é de 100);"
Other solutions like mark-up (commerce/finance) or increase (too general/vague) make sense, but not for this context. Giving this low confidence because the register feels too informal.
Also, without seeing the rest of the document, bonus points may not make sense if the grades are letters rather than numbers.