I think the answer is "No". What you can do (depending on the phone) is to connect to the internet via 3G and then use the phone's WiFi adapter to act as a WiFi Hotspot to connect other devices.
I believe what you were hoping to do was to connect the phone to the hotel's WiFi and also use that same Wireless Network Adapter to act as a WiFi hotspot. The adapter isn't going to be able to perform both functions simultaneously.
Now if you had a Laptop/Netbook with two Wireless Network Adapters installed, you could set up Internet Connection Sharing and do what you want.