I'm puzzled as to why my ancestors Marriage Bond is recorded under St Clement Danes Church and Parish, but in Palott's the marriage is registered under St George's Hanover Sq. with the groom noted as being of St Clement Danes - Should I assume that they stood at the Altar of St Georges?
You haven't said exactly what "is recorded under St Clement Danes Church and Parish" means.
Typically, the printed pro-forma Marriage Bond doesn't specify the church in which the couple intended to marry. Therefore an index entry for that Bond in the London and Surrey Marriage Bonds and Allegations collection on Ancestry will list the given parish of the first bondsman, who is usually the groom.
The intended church (or churches - sometimes there is an alternate) is usually listed on the Marriage Allegation, which precedes the creation of the Bond, and on the Licence which is issued after the Bond. Few licences survive, but many London and Westminster Allegations are included in the Ancestry collection.
The collection of Westminster Marriages on FindMyPast should cover St Clement Danes from 1558 and St George HS from 1725. These are images of original registers (+ I know of some Bishop's Transcripts duplicating PRs at St George) and from 1754 will give you original participant and witness signatures.
FindMyPast is a paid site. If you provide names and dates someone with FindMyPast access might check for you what records can be found before you spend any money. The Pallot's record indicates that it is at least on record at St George HS.
I would also see whether the Ancestry Bond and Allegation collection will cough up the matching Allegation. The indexing there is pretty dodgy, and can require some creative searching to find both records.
Ancestry has a small collection of Marriage Licences. Use the Card Catalogue to search for the keyword "Crisp" among the UK collections. You might be lucky and find your marriage.
Checking these resources should (depending on the date of the event) give you a solid picture of your ancestors' marriage.
ADDED:
I know that around 1812 the Westminster Marriages collection has both original PRs and Bishop's Transcripts for St George. Make sure you get the original PR. The BT will have copies of the signatures but all are written in one hand.
