Sure. But the Apostles weren't the only ones who heard. Lots of people heard Jesus teach.
14 I have given them your word, and the world has hated them because they are not of the world, just as I am not of the world.
15 I do not ask that you take them out of the world, but that you keep them from the evil one.
16 They are not of the world, just as I am not of the world.
17 Sanctify them in the truth; your word is truth.
18 As you sent me into the world, so I have sent them into the world.
Also, let us not forget who was given the keys.
19, Jesus says to Peter, "I will give you the keys of the kingdom of heaven, and whatever you bind on Earth shall be bound in heaven, and whatever you loose on Earth shall be loosed in heaven.
And then we see Peter.
38 And Peter said to them, “Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit.
So even though what you post is correct, it's not specific to the 11 as what I have just posted.