Translation:There are only two bottles here, and we need four.
Marked incorrect for "Here there are only two bottles, and we need four". I see this is the exact same as the "best translation", just a different word order (both are absolutely fine).
I was also given a "correct solution" of "there are only two bottles, and we need four" which, while correct English, fails to translate the idea "here" that was present in the Russian sentence - since "здесь" indeed means "here".
If it looks odd to a non-native English speaker to have "Here there are", I assure you it's fine.
"Here there are " looks perfectly fine to me and your answer is accepted now :)
Now I'm confused! I've just revised the Dative and Plurals module, and it contained sentences like школе нужны такие директора and школам нужны новые учителя. I can't see the difference between those examples and нам нужны четыре бутылки (though I guess нужно was wrong in the singular).