Is intentionally banning an allies hover pick reportable?
If not, why isn't it? Here's an excerpt straight out of the Summoner's Code:
Enjoy Yourself, but not at Anyone Else's Expense
"Short is the joy that guilty pleasure brings." -Euripides
Making games is our business, so it should come as no surprise that we want you to have a lot of fun. We want you to get excited, to have tension-filled moments, and to celebrate your success. This doesn't mean that we're okay with you ruining anybody else's day.
Remember, taking a jab at your friend in the middle of the game is a lot different than making a glib remark at a complete stranger. Someone who is unfamiliar with what you consider playful may take your comment as an attack and react unfavorably. If two players on a team start fighting, good communication and teamwork become nearly impossible. Once communication breaks down, the likelihood of victory is drastically diminished. It isn't uncommon for simple, good natured teasing to spiral out of control into a loss, so do yourself a favor and don't run the risk of sabotaging your own success.
Support Your Team
"[Teamwork] is the fuel that allows common people to attain uncommon results." -Andrew Carnegie
While we all carry a diverse set of individual ambitions and expectations into a game of League of Legends, once we hit the Field we're a part of a team. For better or worse, our fates are intertwined with that of our teammates. Once the game gets into full swing, you have to make a choice between being a positive force for your team, or contributing to your own demise.
Being a good team player begins at champion select. Be open minded when considering the needs of your team. If you're the last one to pick, try to fill a niche in your team that hasn't already been filled. If everyone's picked and something stands out as a deficiency in your team composition, try asking for another player to fill the gap, or change roles to embrace that responsibility yourself. Remember, that by taking on a role you don't normally play, you'll learn more about unfamiliar champions and increase your own skill level.
Once you get in game, try to keep an open line of communication. Warn your teammates if someone is missing from your lane, or if something is placing them in immediate danger. If they're not paying attention to chat you can always try pinging the map. Just remember that one ping is enough! Also, remember that you have to be there to contribute, so don't leave the game or go AFK! Encourage players who are having trouble, and congratulate those who are playing well. And most of all, if you're having a bad game don't take it out on your team!
https://na.leagueoflegends.com/en/game-info/get-started/summoners-code/