Welcome to the forum!
Those speakers should be just fine. Most of the time, receivers are sending less than 1W to the main speakers, and there is even less sent to the surrounds. The louder you play it, the more power gets sent to the speakers. However, there isn't much material that gets played in the surrounds (most of the time). Generally, speakers are damaged by amplifiers that have too little power, not too much power. Sure, you could blow your speakers, but you'll need to be listening quite loudly to do that.
BTW, congrats on your new system!