Thanks for the information guys.

I was worried about the need for a CENOMAR too until a few weeks ago.

I contacted the British embassy in Manila a few weeks ago asking them to clarify the documents I need to bring in order to secure the local CNI. I was told that I won't need to present a CENOMAR to obtain the local CNI at the embassy, but of course my fiancee will require hers. However, they could not confirm whether the municipality in my fiancee's home town would require me to have a CENOMAR in order to apply for the marriage license as it was down to local policy. My fiancee has spoken to her local registrar and they have confirmed I won't be needing a CENOMAR.