In the end, I went back to Square 1, starting with what I definitely knew - I am descended from an Ann M Bowler, who is recorded on the 1891 census (under her married name of Wheeler) as a mother-in-law in the same household as my 6-year-old great-grandfather Charlie Ridgley. She, in turn is the daughter of a Charles Bowler (as it states on her marriage certificate to George Wheeler).
To find out more, I ordered the parish records for Bowler baptisms, marriages and burials from Bucks FHS. From that, I've managed to ascertain that:
Ann M's parents are indeed the Charles Bowler and Ann Newell who married in Fingest in 1808. It looks like they had three children (including twins) in West Wycombe, followed by a son in Fingest, three children in Radnage and one in High Wycombe (Ann M), over a period of 15 years.
Ann M had an illegitimate daughter, Zillah, in 1842.
Ann Newell died in 1831 and it would appear Charles married Priscilla Cato the year after. A further indication that the Charles who married Ann Newell is the same one who married Priscilla may be the presence of a witness with the same surname (Hester) at both ceremonies.
The Charles who was baptised in Farnham Royal in 1790, if he is a different individual to the above, either never married, or didn't marry in Bucks. (Or he could have been a Nonconformist, although I think this unlikely, as his parents weren't).
Conclusion: Coriolanus Charles Bowler is more likely to be my Charles Bowler than the other one, despite the name variation, but I want to see if I can find mention of him in other documents.
Interesting snippet: on the 1851 census, there is a George Harvey, aged 13, living with Charles and Priscilla. One of my great-great-great grandfathers has that name, and he would have been that age. It would be 90 years before a Bowler bloodline (via the Ridgleys) would come together with the Harvey bloodline, though.