Yes they are available for the ARI interface. I’ve translated for version 2.9 so if there are any new words since verion 2.10 they are not translated.
I will have a look at translation again when 2.11 is about to release 
Hi James,
I have followed this topic about the Dutch translation. The ARI looks great in Dutch. Do you know when the other parts will be translated?
Hi gekran,
I will start the translation when FreePBX 2.11 is released (i hope it will be soon but it was promised months ago).
I’m still looking for volunteers as the Admin section will be a huge job to complete. I don’t expect many changes in the ARI though.
You can count me in.
Are you still working on translating, if so, can I help you?