Not if your wifi is on tap as you suggest.
When on wifi everything on the web via your device is absolutely free. All you pay for is the initial wifi cost.
I went to Norway last month and had an iPad and free wifi provided for me via my client for the week. So, first thing I did was quickly set up the web browser and email ( did that via the yahoo web client) all to my own liking and language. It was just like using the ipad at home for the week.