Question about D&D 4E bonus stacking

Question

I have a question related to D&D 4E bonus stacking, specifically related to overlapping type stacking. I understand that in general similar types do not stack, however I'm wondering if there are exceptions. The following two examples relate to my question.

Example 1:

If I have both Wand Expertise (+ 1/2/3 feat bonus to implement attack rolls) and something like Hellfire Blood (+1 bonus to attack and damage rolls with fire or fear keyword) do both stack (i.e. I get a +4 attack) as far as attack rolls are concerned if I'm using a fire or fear keyword power?

Example 2:

If I'm using two items such as Ring of Wizardry (+ 3 item bonus to Arcana checks) and an Opal Ring of Remembrance (+ 4 item bonus to Intelligence checks) do both stack (i.e. I would get +7 to Arcana checks) as far as Arcana checks are concerned?

Essentially, what the question boils down to is whether or not bonuses of the same type (e.g. feat, item, etc.) stack if what they apply to isn't the same, even though they may end up stacking in some instances.

Edit: clarified the post to correct an omission that's important. Also, I'm only asking this as there're some guides that suggest these instances would stack, so I'm unclear on the rules.

Edit 2: After reviewing the errata, the first example doesn't hold, as the feat Hellfire Blood is untyped. However, the general question is whether similarly typed bonuses stack even if the type is similar, even thought the wording isn't.

Answer 1

The word between the number and the bonus is important. For each unique type, take the highest. If there's no word, add them. Be careful of the wording of bonuses, many of them changed when essentials came out to make them more compatible with weapons expertise.

If you have a +2 racial bonus to arcana, a +3 item bonus to Arcana, a +4 item bonus to arcana, then you have a total of +2+max(+3,+4)=+6 bonus.

Example 1: Hellfire blood has no word between the number and the bonus, so it adds to everything. Using a fire keyword power, in heroic, you get a +2 to attack: +1 feat, +1 untyped.

Hellfire blood:

Hellfire Blood Heroic Tier Prerequisite: Tiefling Benefit: You gain a +1 bonus to attack rolls and damage rolls when you use a power that has the fire or the fear keyword.

The confusion over this feat stems from the Feb 2010 errata:

Update (2/8/2010) On the Benefit line, delete “feat.” This change ensures that this feat continues to provide a benefit despite changes to the Weapon Expertise and Implement Expertise feats.

Example 2: Total +4 to arcana checks.