UCL vs Bristol geography

I would just say, at UCL normally you can take language modules as electives if your programme allows, through CLIE. Often you can take 15-30 credits a year of elective modules on most degree programmes. Can't comment on the year abroad offerings though.
I don't think the "prestige" of Bristol is "much" lower. If you are specifically aiming for investment banking or management consulting then UCL is a target uni whereas Bristol is a semi-target I believe which may make a difference. For other things I think they're going to be pretty close.
Have you been to any offer holder days or open days? It might let you get a better idea of what each uni and course is like

The CLIE module thing sounds interesting. I hope it will work with geography.
So long as I have a place, the UCL offer day is this Wednesday. 21st march is my Bristol offer holder day. For geography, Bristol is 26 places lower globally than UCL which is 4th. I love geography and Spanish but I don't want to be a teacher for the rest of my life so I know I have to turn it into something more 'employable'.
I have visited Bristol, its very nice. I think its a bit easier course-wise and workload wise. I've been to London many times, I live not too far out! Place wise isn't too much of a bother for me.
Thank you so so so so much for the information, I cant express my gratitude 🙂

Also looking at study abroad options for geography, they have the option of studying abroad at University Autonoma of Madrid, and it states teaching there is in English and Spanish and at least B2 Spanish is required for that option.
I'd note too that at most unis, even outside of formal modules for your degree, if they have language courses available they often will provide evening/similar non-credit language courses (i.e. not modules as part of your degree, just an additional course you can pay to do for your own interest - these are often open to the public as well but usually you get a discount as a current student or alumni). So that can also be a way to continue your language studies too!
Offer holder days are a good place to ask about option modules (including for example language options!) and where/if they fit into your degree

I currently have offers for UCL BSc geography (international) and Bristol BSc geography + Spanish + yr abroad.
Both offers are AAA, and I'm predicted A*A*A (Geog, Spanish, biology).
I cannot decide between the two.
Pros of UCL: prestige is WAY higher for geography, closer to home, better education. Cons: expensive, doesn't include learning a language in the course, can't study in Spanish on my year abroad.
Pros of Bristol: better social life, can learn Spanish integrated into the course, can study abroad IN Spanish. Cons: much lower prestige, and employability is a little lower too.
I'm not set on a specific job yet, but I have been looking at consultancy/diplomacy/international trade. What would you guys recommend?

I wouldn't say Bristol is much lower for prestige over UCL. Employers aren't going to distinguish between the two in the competitive graduate job market. Go where you think you will be most happiest. If you can commute from home, going to UCL would save you a lot of money and hassle.
I studied at UCL, albeit in a different subject, and l can safely say that UCL is nowhere near as prestigious as Oxbridge in terms of the facilities and academic buildings on offer. Imperial and KCL likewise.

True. For geography, UCL has a leverage as it is global 4th compared to Bristol at global 27th. But in general I 100% agree. I'm gonna have a look around this wednesday and see if I like it! I just want to benefit myself in the long term. Thank you for your advice 🙂