Is there a specific word for a cross-language mondegreen?
I don't think this is a very commonly used term, but soramimi seems to fit:
interpreting lyrics in one language as similar-sounding lyrics in another language.
It is a Japanese term which is borrowed into English.
It has been, or still is, quite a hype in the Netherlands, where the phenomenon is known as 'Mama Appelsap' (lit. mom apple juice), a misheard lyrics from the bridge of Michael Jackson's Wanna Be Starting Something:
Ma me se, ma me sa, ma ma coo sa