Items placed directly into bundles do not unlock recipes or advancements.

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How to test:

1. Open a chest that has two of an item that would unlock a recipe or an advancement.
2. Place one item directly into a bundle in your inventory. No unlock will happen (though it should).
3. Place the other item directly into your inventory. It will now unlock.

Items you can test with are paper (in many loot chests) for recipes and obsidian (in many loot chests) for the "Ice Bucket Challenge" advancement.

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Why this is a bug:

One would expect that – because you can place items directly into a bundle in the inventory, and pluck items directly out for use (unlike a shulker box where you cannot do either) – placing an item in a bundle in your inventory would unlock recipes and advancements.

With shulker boxes, it is understandable that unlocking wouldn't happen. You can't place items directly into them. They are a separate chest that you have to place down outside your inventory to open. And in order to use any items in a shulker box, they need to pass through your inventory before you can use them or craft anything with them.

However, with how freely bundles can be used as inventory slots, I would consider their contents to be inventory and to unlock recipes and advancements as inventory does. If I'm gathering the items for a recipe, I can place them directly in a bundle, and then pull them out to craft with them without the items touching my inventory, and the recipe would not be unlocked even though I gathered all the ingredients and have them ready to use.

With natural use of the bundles, a player can unintentionally miss out on many advancements and recipes that they rightfully should have unlocked.