I've checked the address from the hotel's website and then gone back to old-fashioned methods. (i.e. I've relied on paper maps):
Service 10 starts from King's Cross station, so it shouldn't be hard to find the bus stop. Take this service and alight at Kensington High Street underground station.
Transfer to service 328. The stop will either be the same one at which you alighted or very close by. (i.e. the bus will be going the same way as the one you just left). Alight at Kings Road.
You're then about a mile from the hotel. There are no buses which actually pass the hotel, so my advice would be to hail a black cab for the last mile. (If you want to get as close as you can by bus, take service 11 or 22, to Imperial Road and then walk to the hotel. These buses leave from the same stop, or one near to, the stop where you alighted from the 328, travelling in the same direction).
Chris