Just a follow-up:
I've found there is a standard using a 2048 wordlist of <=4 letters each:
RFC 1751Unfortunately this isn't a very good standard as the words are actually harder to remember than a longer wordlist with longer words.
There is nothing standard in the 4096 or 8192 wordlist space. 16384 may be promising. There is a 65536 wordlist but with that many words you get many words you've never heard of, along with concatenations, plurals, etc. Nothing has been standardized.
It is very disappointing that we do not have a standard. You cannot have a base-4096 (or 2048, 8192, etc) numeric system without defining the numerals (in this case words).
Here's an article I found that explains why laying this kind of groundword is difficult, but I believe it very important to the future of cryptocurrency:
https://www.ivankovic.me/blog/2013/12/26/why-constructing-human-readable-sha256-or-other-hashes-is-hard-part-1/