I think I can help your confusion.
The current Cali AFAIK has the auxiliary air heater only.
You are reading the general Transporter manual, not the Cali supplement.
On some Transporters (and maybe older Calis, IDK) you could specify both when ordering. The manual covers both bases as it’s for a general Transporter base.
As an option it’s not much use for a Cali if you were sleeping in all night as the vehicle will be warm. As a builder though, you need to get away asap on a winter morning, and so it’s a godsend.
In general, the T6.1 based Cali, to my understanding, does not have both, just the aux air heater only.
See here for Transporter explanation.
When I got my T6 Kombi there were multiple combinations of parking heaters. Coolant-based, Air, both, with/without remote. I specified the most expensive option, everything: Programmable parking heater (air) with radio remote control, auxiliary heater (coolant-based) and second battery I did...
www.t6forum.com
I’m not even sure you could spec it. Wasn’t an option I recall. I could dig out my ordering manual to treble check.
I’m 100% sure you only have the std Cali heater.