The effective interest rate for February 2021 Singapore Savings Bonds (SBFEB21 GX21020N) is 0.89% if you held it for 10 years. The minimum amount you can purchase is S$500. If you decide to hold and sell the current issue (SBFEB21 GHX21020N) after 1 year, the effective interest rate is 0.32%.
I wouldn’t put my money into the Singapore Savings Bonds as the interest rate is simply too low. What are the alternatives? You can check my previous post on What can you invest with 500 Dollars?