I'm in high school. I dress plainly, and don't care much about bling. So, ever since I can remember, people have thought of me as poor or less well off. That is until they came to my place and saw the gear I have. My hifi, my cameras, my 24" iMac (most people have never seen a screen that big), no matter which one they saw first, they all said I had to be loaded.
So you'd figure it'd be the same with the iPhone, which is just another expensive hi-tech gadget. It isn't. Aside from the monthly fees (40), it didn't cost me anything, and it's the same for everyone, so lots of people that I know (for a fact) are very much less well off than me have one. And they're not afraid to show that they have one.
So, to answer the OP's question: No. People don't think I'm rich because I have an iPhone.