The language-related posts are hard to relate except in a geographic sense (very little sense of unity). Almost nobody seems to have used #polyglot or even #bilingual as tags (unless I missed some), but I'll go ahead and construct a guide.
I'm very disappointed in the reaction to this first post in the series. After almost 24 hours, only 14 people have even looked at this post, but then again 6 upvotes is pretty good (close to 50%).
Asia
Europe
the Americas
MENA (Middle East & North Africa)
I don't think the #curation tag gets that much traffic, but then again I don't really know who the right audience might be because you are doing something new here. I had similar issues with the #infographics tag because nobody really publishes anything in this area. But once you get your reputation and steem power up (or attract the attention of someone that is in that position) I would say that you would get a much better response. I would definitely publish it in #cn if you haven't done so already.
My title had a bilingual English/Spanish title, but no actual Spanish text (too busy at the time I posted). I have just added Spanish text to my post, but Steemit doesn't allow me to add #spanish (I already have five tags: no changes are allowed after 24 hours).
Thanks for the suggestion. I'll try posting the next article using the #cn tag.