Are you looking for an outdoor entertaining space? When most people hear "garden", it's dirt, plants, irrigation, etc.... A bar or pergola does not belong in a garden.

if you're looking for an outside patio/entertaining space, you might re-title your post and people can respond accordingly. And they of course will ask what you want to use the space for, what sort of things do you need or want, etc.. The more details you can provide, the better.

Or hire somebody locally to come and view the site, discuss how to make what you want happen.

The first issue I see is how small and walled in the area is - like a trough. You need a consultant or designer who knows how to overcome this limitation with particular design techniques.