As far as I am aware it’s currently accepted practice to keep different language versions of albums in separate release groups, though there is no relationship type to link the two (or more) release groups. I made a ticket to add such a relationship and this thread to discuss whether this practice should be incorporated as a formal guideline. The release group guideline as it stands says there is no consensus on this issue, but I have had people tell me (in the context of movie soundtracks) that different language versions should have separate release groups.
Here’s a recent discussion on the topic.
I notice that Peter Gabriel’s German language albums share release groups with their English versions (“melt” and Security).
My personal opinion is that different language versions of the same album should be grouped in the same release group – but if others say differently and if the style guide doesn’t categorically say one way or the other, then the “no consensus” claim appears true. Inspired by this, I put in a couple edits; let’s see how the votes go: