how do you go to Salvo hotel Huangpu from Wusong wharf after finishing the Yangzi river cruise ?

Well, at Wusong Wharf Station, you can take bus no. 952 to the terminus - People's Square, which is about 800-900m from your hotel. You can ask the local people about the exact location of the hotel to reach or take a taxi there then.

Anyway, after your getting off at People's Square, you need to walk forward to Wusheng Road for about 150m and then walk into Guangdong Road for about 700m. Then you will easily find your hotel.