Is there a way of contacting NHS England about the vaccination list?

Your son would be included in the group if he suffers from a health condition specified on the list on the government website. Unfortunately not all health conditions fall into this group. Have you checked it out? 

In respect of NHS England, I'm not 100% what they cover, but they have a contact us page and you could try some of the methods listed on there, it does advise their customer contact centre s busy at the moment though. 

Link - https://www.england.nhs.uk/contact-us/

If your son has a medical condition that is associated with group 6, and you have confirmed this, then he should have no issue receiving his vaccine when it is his turn, regardless of what you think of your GP surgery, it will be detailed in his records, these records don't just come from the GP though, it could be from hospital records and other NHS records held. 

Your best bet is to try and use the contact page I linked to and speak with them. 

I have had the letter, and reminder, last month.  But years ago, when I last saw the g.p. I was disabled but not housebound, as I now am.  Therefore, the surgery says "we have done all our home visit vaccinations, and you were not on the list, proving you are not housebound"  Also "nobody is allowed to speak to the g.p or send an email about Covid" 

I wonder about the new group of people being ordered to shield at home.  At home as in housebound?   Or is that at home as in housebound except if we order you to go out and get the vaccine?   

I was hoping that this new group would allow a chink in the impregnable system of "you are only housebound if your g.p. knows you are, but you are not permitted to tell the g.p. because the reason you want to speak to the g.p. is covid related, which is a banned and forbidden topic, and no patient must be allowed any communication on that  "