A strong two club bid indicates the ability to take something like eight and a half tricks, with a meaningful portion of that being tricks outside the main suit. The test that I use is something like, I can make game if responder has as little as "three and three," that is three well-placed high card points and three cards in my key suit.
The standard requirement is 22 high card points. That's adequate if opener plans to re-bid a major suit after a two diamond "waiting" bid, because 25 high card points and an eight card fit is a favorite for a major suit game.
I don't consider it an adequate holding for a 2NT rebid, because a 22-3 distribution between the two hands is an underdog for 3NT according to these tables of data. Open needs 23 high card points to be a favorite opposite "three."
But the biggest question mark arises when the opener has, say, six of a minor suit and 22 high card points and intends to play in that suit (the hand is not suitable for no trump). The worst problems arise with a diamond suit, because the two diamond response will expose the opener's hand as dummy. A rebid of three clubs is a bit less problematic, but it still rules out "double negative" responses such as 2NT or three clubs. To compensate for these problems, I need 25 points or more to open two clubs with a minor suit target.
Does such a three tiered structure (22 points for a major suit game 23 for 3NT and 25 for a minor suit game) make sense?