Ah ha, the drainage problem solved, at least. That's good. Having the drain there will also help a lot with keeping humidity up.
Still supplying enough light to keep the plants healthy especially through the short days would be your challenge, I think. Are there windows in the garage door? As I mentioned, supplemental lighting is probably going to be needed. You could run it on a timer after hours and early in the day when the pub is not open so as not to destroy the ambiance. (I'm Canadian, originally from Vancouver, btw. I know those short winter days!)
You could plant the vines in 3ft. window boxes over the drain and let them grow up the wall. But as I mentioned, a twining vine that would use a trellis might be a better option if you don't want to damage the brick. Easier to keep it in bounds as well, and to remove if you had problems. Most of those would need more light than ivy or creeping fig, though. Hm, there are some beautiful variegated ivy types that aren't nearly as vigorous as the kind you see outside in landscapes. They might work for you and be really pretty.
See if you can find a building with ivy growing on brick, and take a close look at how it attaches. You'll see what I mean about how tenacious these clinging vines can be.
For watering, a drip system on a timer would be easy and inexpensive. But every so often, you'd need to spray down the leaves to keep them looking good. They gather dust and dirt, as well as cleaning the air in general in your space, a nice perk. But they need "rain" once in a while
