If you want to specialise in background concept arts, it'd be good to add interiors and exteriors with architecture. Your third image is your strongest in my opinion, and your first would benefit from the structure being actually designed and given attention to (right now it's to plain).
Personally I think you are great! Only thing I would watch out for is make sure as an environmental artist your figures skills aren't put on the back burner. There's nothing like seeing a brilliantly painted background with a horribly awful figure to spoil it all. If you get that down (and I really can't tell if you haven't already as your figures are so small), then I'd say you ought to get work just fine.
Nice! I think @freiheit and @lithriel have some good advice there, agree with their points especially about rounding out your environments with some more interiors. Even if you want to specialise in environments (which you are obviously very good at) it wouldn't hurt to have a range of other work, e.g. characters props etc, to demonstrate versatility to employers.
Thanks for the help everyone, its definitely appreciated.
As for your suggestions, I think I will start working on some interior spaces: ie rooms, halls, architecture, etc. Maybe I will do a character at some point but I feel there are plenty of people who specialize in that kind of thing.
You've got some really nice atmosphere going on in these pieces. One thing that jumps out at me immediately is that you could define all your forms a little better (the 3rd painting of the mountains is more successful at this), and as another poster mentioned, you could flesh out the design elements of your architecture a whole lot more. Interiors would be great to see.
I think some of your character work is pretty good. Just keep going and improve with each piece.