syncing iPhones on a PC

My wife and I both have iPhones.  She’s had her’s for a bit and I just got mine. On our Windows PC she has iTunes set up and she has synced her iPhone  with it.

She wants to sync my iPhone up with it too. Someone told me that if you use the same PC Users account and you sync up two iPhones to iTunes, the phones get a bleed over of the other persons apps and stuff. Is that true?