Nanning Metro is the metro which opened last month.
According to a picture of Huijiang Zhongxin(Exhibition Center) Station, Zhuang language is written above Chinese Characters.
https://zh.wikipedia.org/wiki/%E4%BC%9A%E5%B1%95%E4%B8%AD%E5%BF%83%E7%AB%99_(%E5%8D%97%E5%AE%81)#/media/File:%E5%8D%97%E5%AE%81%E8%BD%A8%E9%81%93%E4%BA%A4%E9%80%9A%E4%BC%9A%E5%B1%95%E4%B8%AD%E5%BF%83%E7%AB%99%E7%AB%99%E5%8F%B0_(1).jpg
BTW, Local language(dialect) announcement is delivered in the following metro systems in Mainland China.
・Shenzhen Metro→Cantonese
・Guangzhou Metro→Cantonese
・Foshan Metro→Cantonese
・Dongguan Metro→Cantonese
・Shanghai Metro Line 16→Shanghainese
・Fuzhou Metro→Eastern Min
On buses, the following cities in addition to above cities install announcement in local dialects.
Shantou:Southern Min
Meizhou:Hakka Chinese
Xiamen:Southern Min
Qianzhou:Southern Min
Putian:Pu-Xian Min(Partly)
Suzhou:Shanghainese
Wenzhou:Shanghainese
Though CCP(Chinese Communist Party) is supposed to try to extinct minor cultures, local languages(dialects) announcement in public transportation seems to be in momentum.