I don't think you're asking the right question because 1 gm of protein possesses 4 calories, the same number as 1 gm of carbohydrate. So if you increase your protein consumption, you'll be increasing your caloric intake as well (holding all other things equal). To ask which is more important doesn't make a lot of sense because there is a positive correlation between the number of calories consumed and the number of grams of protein consumed (all other things equal).
A different way to approach your question would be to evaluate the balance of proteins, fats, and carbs (simple vs. complex). It's a basic rule that if you consistently place yourself in a caloric surplus, you'll gain weight. Now the composition of that additional weight can vary dramatically from person to person based on a slew of variables.
So if you're trying to build LBM with minimal fat gains, you should consume a diet rich in proteins, quality complex carbs, and a little bit of healthy fats. If you're eating cleanly, that means you're avoiding all junk food and a lot of simple sugars. Just continue what you're doing and eat small meals on a regular timetable. It sounds to me like it's working well for you.