It seems that in English there is a standard set of words that one can use to form a phrase representing a relationship. I would bet you could figure out Sino-Luna, or Franco-Bovine despite the fact that they are "made up" relationships.
My sense is that this is not the case in Chinese, as the components of the "relationship phrase" loose some of their individual meaning:
You can see that when separated the Chinese terms become meaningless.
I think this is why it is easier to come up with these phrases in English - one can simply interpret each side and process the combined meaning.
In Chinese, unless the phrase is already in common usage - it would be hard to invent in any meaningful way. (As an extreme example, I would assert that no-one would read 法牛 to mean "The relationship between France and Cows" :)
P.s. It doesn't seem like Ponto-Mediterranean is common in English literature either. See ngram.