Whether that statement means that the angels don't understand Aramaic, or that they can understand it but consider it vulgar, is a topic of debate among the various commentaries. There is a summary of the whole issue, with extensive sources, in Beis Aharon, s.v. אין מלאכי השרת מכירין בלשון ארמי.
Maharsha (to Sotah 33a) explains that the specific mention of Aramaic is not to exclude other languages, but on the contrary: even though it's closely related to Hebrew, and even though it's prestigious enough that the original Aramaic Targum of the Torah was given at Sinai (Megillah 3a) (plus, also, parts of Tanach are written in it), still the angels consider it a low-class language as compared to Hebrew. All the more so, then, that other languages - which don't share these advantages - would be in that category too.