that's an interesting question!! I have ever thought about it before. But I'm thinking there are still many more meaningful gifts. 
And I will give them to my lover ^^
Well, Its an interesting idea. However, I think I will not give it as a wedding gift and bitcoin is very expensive so that I will not give it as a wedding gift. In addition to that, wedding is one the important things in your life and if you are a rich person you could give bitcoin as a wedding gift but I think if you love her or him you should give the things that she or he really want. And I will give them to my lover ^^