I can't think of any off the top of head and I sell bathroom gubbins (and check out competitors fairly regularly as part of it) Most cabinets will be water resistant - designed for a humid room, but there does seem to be a gap in the market for wet room furniture. I get asked for it a lot!
I'm curious myself now, so shall go and have another google...
We've just had the same fruitless search. Our shower cubicle is quite big and the water doesn't reach the end wall. DH was quite keen on a cabinet although I wouldn't mind a shelf. I think he might make a corner shelf thing covered in tiles. Not sure. I know what you mean about wanting the bottles hidden, though - I hate them. One solution I came across is to fix dispensers to the wall (not keen), or buy poncey decorative bottles and decant, which I'm sure I'd soon get bored with. Zara have some nice bottles.
If you can't find anything else you could always get those then line the inside of the doors with something. There is a company called Keter which does solid and mirror door plastic cabinets, but it doesn't have a UK distributor although it does allow you to browse even after you specify you're from the UK It's a big tease, but maybe something to keep an eye on?