Like PP said, there's black tie and there's black tie. I've been to events labelled black tie where this would be completely appropriate, and I've been to others where its all long evening dresses. Honestly, only you know the bridal couple and where their expectations lie, or even if they are high maintenance about these things.
It reminds me of a black tie wedding I went to years ago, where a friend came in a 60s style mini dress covered in those iridescent, hugely oversized sequins - she looked phenomenal and not in any way out of place.