Savings: Two jackpots a month, should you be topping up your Premium Bonds?

gambling fruit machine showing a winning line for payoutPremium Bonds have always been a popular option for savers tempted by the chance of winning the jackpot and tax-free returns on their savings. But ERNIE is changing, from 1st June the maximum amount you can hold in Premium Bonds will increase from £30,000 to £40,000 and from 1st August there will be two £1 million jackpots each month. So should you be tempted to buy Premium Bonds, or top up if you already hold the maximum of £30,000?...