It's way more important to play in tone than "in tune" , because that is all relative. Although I struggle with groups that play sharp, I'm always playing in tune with them. I found that playing in tune with the group instaed of with my ear was far more important. It took me a couple years to figure out it didn't matter how absolute my pitch was, because if I was playing at 440 and the rest of the band at 445(haha), I was the one who stuck out and sounded wrong.
Here is a good example I'm not shy to share with you. This is a recording from when I was in high school.
http://www.jonkratzer.com/spring2.mp3
I doubt you can hear by the recording, but the band was horribly sharp. Listen to the first few bars and you can hear the pitch adjusting to the band. It's not a catastrophe, but believe me I've had a few.
Worry about your tone and playing intune with the ensemble, and you'll be just fine.