I do not believe that itch.io's system will give you the addons unless you paid for them with your initial purchase, unfortunately. You should be able to check your download page to be sure, of course.
I see. No, I don't see the option to download the addons. I was interested in the winter sale, but I don't recall the bundle specifying if it comes with the addons, given that three of the VNs specify buying at full price of $5 to get the addons.
The current 50% off bundle does not come with the addons, but you can still buy the games individually and pay a little extra on each to get them. Sorry about the confusion, it's one of those itch.io things that I don't have control over.