In order for us to appropriately answer this, you’ll need to answer a few basic questions. Have you met the person yet you intend to marry? Have you and your fiancée decided that you’re enjoying your engagement so much you’re going to put off the wedding for another decade or two? Is your wedding tomorrow? Your answers will dictate exactly the best way to save for your wedding.
If your wedding won’t be held for the next three years or so, you’re probably going to want to invest that money, so at the very least your savings will grow at a pace equal to inflation. (By the time you get married, who knows, renting out the function room on the space station could cost millions!) How far away your wedding is, and how much of a stomach you have for short-term volatility will dictate how much of your wedding savings should be invested in equities, AKA stocks, which can have wild up and down swings, versus low-risk government bonds, which are more stable, but offer less potential for growth. The closer your wedding date is, the more conservative and the less vulnerable to fluctuation your investment should be.