I expect you've already done all this - if so sorry!
Take a look at the pdf download from the same site linky
Scroll down to the 164 bit, top of page 4. Last 164 entry is "V6 24V, Q.V. G.D. " The GD means right hand drive (I think)
The bit you want is I think that for engine 66302. As you know my engine's earlier (66301 - this can be verified from ePer) Yours is a CEE F2 car and M6 engine I think.
You know how to do this...
1. Start ePer and select Alfa Romeo
2. Select 164 model
3. Don't pick a version, but selectthe item "Browse by Vehicle Data" below the two little pictures, middle of screen.
4. Select model 168¦ 164 Super from the drop down.
5. Enter the last eight digits
of your VIN in the text box to the right. Click the magnifying glass to the right of that.
6. Select your MVS from the list if offered. The screen will show the details of your car and this should match what is on the plate riveted to the car.
You will see the "engine stamp" I reckon this should be 66302!
Back to the Bosch list: you can identify the bosch part number here now, it's the same as mine. This is where I cannot make out the lists - what's the W10 and W16 thing? Will need to speak to a Bosch service centre. The universal part0 258 986 586 looks to be OK. If you don't want that, looking at the entry for the Q4, I notice the universal part is the same as for our cars. The Q4-specific part is the part number you quoted so I wouldn't mind betting you are right - it will be OK for us.
Crikey - sorry to make such hard work of this only to reach the same conclusion.
The list price from Alfa isn't so very much more than this place though but I note your car and mine have different part numbers listed in ePer. Don't know why.