300 inclusive UK texts and 500MB Web provided you have topped-up between £10 and £14 in the previous month.
Unlimited Wi-Fi is available at any of the 9,500 Wi-Fi hotspots from our partners The Cloud and BT Openzone. Excessive usage policy and full terms apply. At the end of the twelve month free period you will start to be charged £10 per month for the Web and Wi-Fi Bolt On.
As I said you are confusing two things the Text and Web tariff and the iPhone Web and Wi-fi bolt-on.
As I also said, Network Data refers to data use on O2's (2G & 3G) network, it does NOT include wi-fi.
Completely separate is the web and wi-fi bolt-on. You can add this to any tariff (eg favourite place) and provides you with unlimited network data and unlimited wi-fi through partner hotspots. This costs £10 a month.