You are right, that document is mainly about funding for IVF so not applicable to you as you are not eligible due to having had a child already. In your situation with known PCOS and having required fertility clinic in the past, the GP should be able to re-refer you if you've been TTC for 6 months with no success. The NICE guidelines have the following criteria for fertility clinic referral (for any fertility treatment, not necessarily IVF), which usually would require the GP to perform some baseline investigations first:
When should I refer a couple presenting with infertility?
For woman younger than 36 years of age:
In general, consider referral (for further assessment and management), along with her partner, if history, examination, and investigations are normal in both partners and the couple has not conceived after 1 year.
Consider earlier referral if the following factors are present:
In women:
Age 36 years and older (refer after 6 months).
Amenorrhoea or oligomenorrhoea.
Previous abdominal or pelvic surgery.
Previous pelvic inflammatory disease.
Previous sexually transmitted infection (STI).
Abnormal pelvic examination.
Known reason for infertility (for example prior treatment for cancer).
In men:
Previous genital pathology.
Previous urogenital surgery.
Previous STI.
Varicocele.
Significant systemic illness.
Abnormal genital examination.
Known reason for infertility (for example prior treatment for cancer).
From what you say, you fit these criteria for fertility clinic referral, even though you won't be eligible for IVF. Your local area should have some sort of referral pathway including tests you might need before referral if you've not had them already, which will look something like this:
clinox.info/clinical-support/local-pathways-and-guidelines/Clinical%20Guidelines/Fertility%20IVF%20Referral%20Pathway%20part%201.pdf
www.oxfordshireccg.nhs.uk/professional-resources/documents/clinical-guidelines/gynaecology/fertility-IVF-referral-pathway-part-2.pdf