You can take a bus to Tunxi, Hongcun-Yixian, Yixian-Tunxi all start in cycles, with an interval of 15 minutes. The bus from Tunxi to Wuyuan passes through Jiangwan, and the specific route is Shandou-Jintan-Huang Mao-Jiulong-Dafan-Zhentou-Jiangwan-Wangkou-Qiukou, at 8:30 am, 12:30 (this information is old, so I'm not sure whether to take this route).
It is recommended to consult the station directly, Yixian: 0559-5522026, Tunxi: 0559-256666.
I hope it helps.