Plug in your bank points, the base transfer ratio, and the bonus percentage. See your effective ratio, the partner points you actually receive, and how much cpp uplift you earned versus no bonus.
A transfer bonus multiplies the base ratio. The cpp uplift is the percentage improvement on your effective bank-points cost — equal to bonus / (1 + bonus). A 25% bonus is a ~20% cpp uplift; a 50% bonus is a ~33% cpp uplift.