Ok this might sound confusing. My wife and I share the same iTunes account. She has hers on her pc and me on my mac. So we can share apps we d/l but cant share d/l music from iTunes? Also if we both have iphones our contacts won't get mixed up?
If you both turn on home sharing, you can browse each others iTunes libraries, and copy paid apps and music between the computers. You can then sync them to both iPhones.
You can use the app on both iphones. When you "buy" it on the app store app on the 2nd iphone, it will realize you already paid for it and download it a second time. You don't have to use computers to manage apps.
Any app, music, movie, books, etc. purchased through iTunes can be played on an unlimited number of devices as long as those devised use the same Apple ID. The best thing to do for multiple people in the household is turn on "home sharing." When you purchase an app on your computer with home sharing turned on, the app will transfer over your wifi connection to all other computers in your household with the same Apple ID (total of 5 computers are allowed). In other words, with home sharing turned on, my family of 4 is able to share each others purchases without any additional cost. If you purchase the app on your iPhone, just sync with iTunes. Now the app is in your iTunes library on your computer. When your wife opens iTunes with home sharing turned on, it will recognize that your library has added a new app, and it will transfer it to her computer. Now she will need to determine if she wants to sync it to her iPhone through the sync options. We absolutely love home sharing.