The effective interest rate for April 2017 Singapore Savings Bonds is 2.27%. Seems that interest rate is declining but it still beats the traditional fixed deposits. Banks are also slashing its interest rates. A good example will be OCBC 360. (Read more here: OCBC 360 Account Makes Earning Additional Interest More and So Complicated)
While browsing the Singapore Savings Bond website, I came across the FAQ they have put up on their website.