Marble is porous, it will stain (red wine) and etch from cleaners and acidic liquids (lemons, limes ect..) Its the curse and joy of an authentic material. Some people invite the patina but others do not. If you want a low maintenance material quartz would be a great solution. There is some porosity in this material too so do your homework before you choose. i have a very white quartz in my kitchen (6yrs) and don't have any permanent stains. As for your backsplash, you could wrap he counter material up the wall, it would look fantastic.

Since it's a bar, why not select something more dramatic? There's beautiful stones that can do wow in a fun space.

I would do something light, like your second choice. Marble is beautiful, but for a bar, it might be problematic. We chose quartz. They have now all kinds that look like natural stone We picked Cambria torquay since we wanted something simple and a bit warm since we have walnut cabinets