That's a very interesting topic and I have just heard it a few days ago in the Coast2Coast show - yep, it can mean that you are attracted to the person, but it can also mean that there is something in that person you appreciate, maybe you wanna be like him/her... Of course it was just an opinion of the guest lady who was good at analyzing dreams, I do think that you better just look into yourself and find out how you feel about it, because your own dreams are your own personal language to let you know what's up with you on the subconscious level...

I used to have, and still have sometimes, dreams with my sister, of, ehem, well, highly erotic dreams, of course in the dreams I am all crazy for the whole thing, and when I wake up remembering it weirds the hell out of me! :S:S:S It was bothering me for months and months, until I asked a guy who was a parapsychologist buddy of mine, and he said that I was having them because deep in my heart I loved my sister (as a sibling only of course - we were having an extremely bad relationship in those days), and my subconscious mind was trying to ask me to try to get back a little closer to her, to have a more harmonic sibling relationship with her...
Now that we are so far away from each other we are both enthusiastic about talking with each other online, there is still a little tension and discomfort, at least I can feel it in her through the way she writes, but she sounds happy whenever she hears about me... I started to have more dreams of her lately, mostly we are together in them, and whatever is in the dream we go through stuff together, solve things together, so we are totally like two very best friends, or two real sisters I guess...

So yep, it veryverymuch depends, you just better ask yourself and be honest to yourself, that it what works the best! ^^