"But his delight is in the law of the Lord; and in his law doth he meditate day and night." (Psalm 1:2)
From this. When you read "bottles", Jesus is referring to wineskins that would need to be replaced with the vintage (?) so as to prevent the skin cracking from age. And so when you put "new wine" into a "new bottle", they can expand and contract with one another, preserving both. This a beautiful parable by way of analogy that has more depth than one might think at first glance:
"Neither do men put new wine into old bottles: else the bottles break, and the wine runneth out, and the bottles perish: but they put new wine into new bottles, and both are preserved." (Matthew 9:17)
And so, we have Elihu. The "fourth wheel" of Job's "friends", it never explicitly states that he really doesn't know what he's talking about. I feel, though, that with a book of Job's caliber and breadth, one must necessarily come to this realization for themselves--having made this kind of mistake for oneself--after not just reading but living through that old part of their mind that Jesus would be sure to lead you out of:
"Behold, my belly is as wine which hath no vent; it is ready to burst like new bottles." (Job 32:19)
Here's the thing about Elihu. He has a lot to say and he's young. Wanting to make an impression on the aged men sitting by who were chiding Job, himself someone to look up to, he feels he has to speak the "right words", the ones he has in possession. The thing about wine (and volcanoes, too) is that it must necessarily wait. We must wait. The Bible contains the very life of God, distilled into words that anyone literate can read and realize. But there enters into this thing the act of "meditation". The deliberate mulling over of God's deep statements that you think you understand but (forgive me), you actually don't. So:
"Even a fool, when he holdeth his peace, is counted wise: and he that shutteth his lips is esteemed a man of understanding." (Proverbs 17:28)