I know the less prestigious unis often have lower entry requirements, but with Bristol I really don't think this is the case. It's probably just because the language courses really aren't that popular, in which case they don't need to give as high offers as, for example, English, which is an incredibly popular course (average offer AAA). Also, I doubt a uni as good as Bristol would allow any of their course areas to lack in quality, as they want to be seen as a good uni all round.
I went to an applicant visit day yesterday and was really impressed. The professors and current students were all very friendly, and it is constantly stressed that Bristol is strongly based on research to give the best possible education. They seem to have plenty of socs and groups to join, one I remember included a fortnightly gathering at a pub, where students gathered and just spoke German all night, which is great considering how hard it can be to find someone to properly practice with. I'm sure they'll have something similar for French, and possibly also for Portuguese. I also loved the city, which is beautiful and said to often be sunny and warm (it certainly was yesterday!).
The course I've applied for, German and Spanish, is apparently the rarest combination and the least popular course. I'm assuming this is the reason my offer is only BBB. Spanish and French is incredibly popular and they have to turn many people away every year - the average offer is AAB-ABB.
I wouldn't let the entry requirements bother you. It is a highly acclaimed uni in a fantastic location (compared to where I live in Yorkshire anyway!), and is 14th on the league table for languages -
http://www.guardian.co.uk/education/table/2011/may/17/university-guide-modern-languages-linguisticsI'm not saying definitely go there, but don't rule it out until you've seen it for yourself