If your bar stool area is nearby other chairs, you might consider coordinating the seating throughout the space. This isn’t to say you should run out to the nearest furniture store and buy a set of identical-except-for-height chairs and stools. But you could consider keeping one style element similar for consistency, such as the wicker seats in this photo.
Fabric, as opposed to leather, tends to be a little bit more versatile. It comes in many different textures, not to mention the array of colors and patterns. Also, fabric is easier to work with. Fabric-upholstered furniture, in this case bar stools, make a space feel more casual and thus more comfortable and inviting. But their rusticity can be toned down by incorporating various accessories into their design or by pairing them with certain types of furniture or certain colors and materials.
Another good example of simple design that fit in a variety of interior designs is that featured by Stool_One by Magis. Here you can see it displayed in a contemporary setting where it complements a large kitchen island.
For vintage-modern interiors, a different type of design is required and the Rutland counter stool definitely has it. It has a strong metal frame and a few gentle curves that soften its industrial appearance.