I know it's been a while, but I'd love to see some images of the end result!

I'd google restaurants in water front locations like St Kilda, Noosa, Bondi, Port Douglas (or Nantucket, Muskoka or Hamptons) and see who has a look that's similar to what your after. Then we could help with more focussed suggestions. Coastal can have many versions. Have you finalised wall, ceiling and floor finishes?

If you pull off the mosaics think about trying to get a subway style tile that matches your wall tiles. Update the vanity with gloss doors and more modern handles and have a wider vanity with either an undermounted sink or above mounted sink (undermounted will give you a cleaner eyeline and easier cleaning) and caesarstone benchtop is a great material to use - it's dead easy to clean. I'd keep the colours light matching your tiles and bring colour in with towels and items such as soap holders etc which are easy and cheap to change. While your at it, have all the grout professionally steam cleaned and if required re-grout (and don't forget to seal the grout - make a big difference). Get rid of the shower caddy hanging off the shower and put in glass corner shelves in the shower.

An outstanding job with one of my preferred material.