Protein power is only useful if, for any practical reason, you're currently not able to eat a sufficient amount of proteins. If you can, getting proteins from real food is almost always much better than getting them from powders.
For creatine, it doesn't really makes anything for muscle growth but it helps to train harder, a bit. It is very safe so the main thing to think about is just whether you're willing to pay the $$$ or not. Some people don't even respond to creatine at all, while for other people it can result not only in longer training sessions (a few sets more) but also in a bit more strength (up to 10% more).
For the strength part, coffee and a few other "booster" components can help as well. For the endurance part (which, personally, is the only part I feel) you would get almost the same benefits from just splitting your training into smaller sessions or having an intra-training high-carbs shaker.
PS: you also have a small visual effect with creatine, your muscles will look bigger because they will be filled with more water. A small effect which disappears when you stop taking creatine, and doesn't have any effect on muscle growth and strength.