Is the bonus already added to the wallet or is that something for after the sale?
Bonuse are being added on the fly.
No they aren't. Math doesn't work that way.
Of course it works this way.
The 20% bonus was not notable during the first 24 hours because EACH btc investment had the added 20%. This way it made no difference because your share was the same as if no one had gotten a bonus.
Now as the proportion of 10% and 5% bonus investments get bigger during april and may, your 20% bonus will become more and more notable.
example of how the bonus is added on the fly:peter 100btc (counts as 120btc)  //20% bonus
bob 50btc (counts as 60btc)  //20% bonus
__24h passed__
max 50btc (counts as 55btc)/10% bonus
before the 24h passed the bonus did not make a difference. peter had 66.6% of the waves and bob had 33.3%. wether the 20% were added or not.
after the 24h period the bonus becomes notable as bob now owns 25.5% of waves and max owns only 23.4% but they both paid 50btc.
No, it doesn't. Because that is a shitty approximation and not an actual representation of the bonus. Of course you can wildly guess, but that doesn't make it true.