Hold down shift during loading.
After you've started the game, the XML files are cached (temporary saved), and when civ restarts it will load the cached files, because this is faster.
-> in your case, the normal civ files are loaded instead of you edited files.
Holding down shift will clear the cache and really load your mod.
If you want to go further in modding you should disable caching in the .ini file of Bts.