Is there a subway from Guangzhou South to Home Inn?

Yes. According to Baidu Map, take Metro Line 2 (direction to Jiahe Wanggang) from Guangzhou South Railway Station, transfer to Guangfo Line (direction to Lijiao) at Nanzhou Station, and transfer to Metro Line 3 (direction to Tianhe Passenger Transport Station) at Lijiao Station direction), transfer to Metro Line 5 (direction Jiaokou) at Zhujiang New Town Station, get off at Wuyangcun Station (Exit C), and walk 770 meters to Home Inn. The whole journey is about 21 kilometers and takes about 51 minutes.