They shouldn't be directly wired to the input jack. Inside of the speaker is a crossover that directs the correct frequencies to the correct drivers. If you bypassed that it wouldn't sound very good.
You could bridge the amp and you'd get 100 watts peak into one speaker. Running the amp bridged at it's peak output will kill it pretty quickly.
Something like this (link) would be better suited for that amplifier but I don't think it would give you what you're looking for.
If you're already considering buying two speakers at $320 why not get a powered speaker such as a JBL EON (link) or for less pyle pro powered speakers (they are cheaper, but you get what you pay for) and a power inverter
The EON has a little more low end than the Behringers and you won't need to worry about getting a high pass filter to protect the speakers, like you would need to with the behringers (if you were to get a more powerful amplifier). And just one will be plenty loud - probably more so than your buddy's.
Another advantage is you could use this speaker anywhere else you want to.
EDIT: Just realized this was almost a month ago... so... yeah.
If I understand this correctly, you want to be able to take whatever audio is playing through your AVR (a movie, or just streaming music) and have it playing in various places? In other words, will you only ever be using that ONE source (AVR) for all four of your zones?
Speaking strictly for surround sound in a 'home theater' type setting, this is a horrible idea. But I get what you're trying to achieve here. Hopefully you're not looking for very accurate surround effects, because you'll basically end up with a singular Center channel speaker (don't buy a soundbar) and then rely on in-ceiling speakers for the rest of the channels. But here's what I think you'll need:
Get a newer AVR that has a Zone 2 option, like this Yamaha RX-V685 for $500. That way, you can send an entirely different source of audio to any of your other zones while watching a movie in the living room (here's an article on it if you're unfamiliar). Such as, your friends come over to socially gather (jeezus I can't wait for this again) and ya'll sip cocktails on the deck listening to a fabulously-curated Spotify playlist while the little ones watch a movie in the living room. Best yet, you can still use your existing gear, or at least the sub.
Then grab an 8-channel speaker selector from Monoprice for $30. ALWAYS leave the impedence matching enabled on this thing or you'll burn up the AVR amp real fast. That'll send audio to 16 speakers, or 8 stereo zones. But it's the same audio across all speakers hooked up to the selector. You'll have to manually select what pairs of speakers you want playing, though. If you want something a little more high tech, look at HTD's whole house audio for stuff like that. It'll cost a lot more, though.
I'd say that you should spend more for the speakers that will be playing anything movie related in the living room. So spring for a nice center channel and 4 in-ceilings there, but everything else doesn't need to be fancy since it's mostly background (non-rager) listening levels. Look for in-ceiling speakers with higher sensitivity ratings though, as close to 90db that you can get. The speaker selector is going to interrupt a bit of power and volune trying to impedence-match 10+ speakers, so the louder a speaker can get with less power, the better. Some options: Micca M-6C (87db) | Monoprice Alpha
The Yamaha speakers you selected should be fine for movies/TV. For the porch, get Polk Atriums or Dayton IO65XTB's.
I'm not an expert in any of this, but I do have some experience with the speaker selectors from Monoprice and can vouch for their products in general. Good luck!