Cardiff

Urban Tap House - for Tiny Rebel and others on cask (burgers also recommended)
City Arms - good selection of well-kept cask ales
Brewdog - Brewdog beers, decent guest and apparently good burgers/hot dogs too. Bit pricey though.

These three are also within a few hundred metres of each other, near the Millennium Stadium.

As for bottles, try Discount Supermarket on Whitchurch Road and the Bottle Shop on Pen-y-Lan road. A bit out of the way of the city centre but bottles in the bars are extortionately priced. Both shops normally have a good range of Welsh beers as well as good new nationals (Siren, Buxton, Wild Beer, Kernel, etc)

Also make sure you visit the castle! I work in the Royal Welsh/Queens Dragoons Guard museum there.

When are you visiting?

 

When you say stadium do you mean the Millennium Stadium or the stadium where the football will be, Cardif City Stadium?
There are one or two places out that way worth visiting on top of the city centre bars.
Also, bump this closer to the time and you may find some events happening, brewery open days, fests etc.

 

To be fair both are pretty near each other (and the town centre).

Shame you'll be here about a week after the big beer festival. I'll be long gone by then unfortunately.

 

This match is in the Cardiff City stadium, you are staying in the best place and it will be easy to get to the game, taxi, bus train etc, even a walk with a good pub or two on the way.

 

I wrote a little beer guide to Cardiff on my site: http://themissingdrink.com/beer-in-cardiff-beer-quarter/

My day job is at Urban Tap House, so I may be a little biased. Might take you up on that offer of belgian beers too, and repay you in some Tiny Rebel beers?

 

Which place will the Hop Bunker be replacing? Pizza Hut or Lloyds bank? I was about to say Bogiez but I think that's where they're building those flats now (?)

 

That building is indeed student flats, but Hop Bunker is indeed going where Bogiez was.

http://www.walesonline.co.uk/whats-on/food-drink-news/craft-beer-hopbunker-set-old-8613978