Wedding cakes are great as they differ from birthday cakes because they are telling the story of two people. What this means in my head is that you can start to have a bit of fun with the flavours, you are trying to please two people and so I say go for what makes each of you happy.
For example, the bride wanted salted caramel, the groom strawberry and vanilla. So we ended up with an apple and salted caramel bottom and top tier, and then a blackberry and vanilla middle tier. Covered in a caramel swiss buttercream which all tied in nicely with the Autumnal time of year. Topped off with a lovely cake topper.
This was the largest cake I have ever made and we had to sacrifice the chilling of the beer and wine to fit it in the fridge. Which no one seemed to mind.