Every offensive and healing spell in the game has a magic type associated with it. You can see this in the Magical Archive in the in-game Cyclopedia, and also in the spell library of the website.
The list of possible magic types is:
- Death
- Earth
- Energy
- Fire
- Holy
- Ice
- Physical
- Healing
- Variable
A spell will only have one type. "Variable" is a special magic type that knight and monk spells have, since their damage type depends on the weapon used.
When you cast a spell, if the spell scales with magic level, then the game will add together your magic level and any magic type bonus, and it will use that to determine the power of the spell. For example, if you cast Energy Wave, the game will add together your magic level and any "+ energy magic level" perks you may have. So, if you have magic level 150 and the +2 energy magic level perk from sanguine coil, it is equivalent to just having 152 magic level.
So to answer your question specifically, "healing magic level" does not give you a higher bonus than standard magic level when it comes to healing.
Note that paladin healing spells are not classified as holy, they are simply the "healing" magic type. Any "+ holy magic level" perks will only affect holy damage spells, and not the healing spells, despite them having "san" in the name!
