Your phone lines has the $30 Data Plan feature for Personal Email and Web. Yes, that data plan is unlimited data for internet and email for your line only since it's a feature only available for your smartphone. Since your line is a secondary $9.99 line on a Nationwide Premium plan, you also have unlimited text and picture messaging. As you said, you pay extra for Droid apps that aren't free and also if you subscribe/download any Premium SMS (text messaging).
Your brother's phone is the primary line on the Premium plan, so his phone must be what VZW calls an Enhanced device, not a smartphone, but has multimedia capabilities and full HTML browsers, e.g.., enV Touch, LG Dare, LG Voyager, enV3 and Samsung Rogue to name a few. The Premium and Connect plans were designed/market for users of these enhanced devices to give them unlimited data and messaging options, not smartphones, and to save money instead of having to add data features a la carte. It sounds like you are all set up on the right plan.
