Subject to confirming George's father's name from his marriage certificate, this could well be his baptism:
Christ Church Spitalfields
27 Feb 1831
George Whiteman - George and Jane, of Pelham Street, labourer
There is also a George Whiteman baptised at Bow in 1829 to a Thomas and Frances, which obviously doesn't tie in with his place of birth on the Census but the marriage certificate would confirm definitely who his father was.
There are two other baptisms to George and Jane in Spitalfields, William in 1833 and Joseph in 1838.
The family appear to have moved to Berkshire by 1841:
Uffington
George Whiteman, 35 years, born Berkshire
Jane Whiteman, 40 years, born out of county
George Whiteman, 10 years, born out of county
William Whiteman, 8 years, born out of county
Joseph Whiteman, 2 years, born out of county
Jane Whiteman, 6 mths, born Berkshire
This ties in with the 1851 Census:
Compton Beauchamp
George Whiteman, Head, 48 years, Farm Labourer, born Knighton, Berkshire
Jane Whiteman, wife, 51 years, born Send, Surrey
William Whiteman, son, 18 years, farm labourer, born Spitalfields
Jane Whiteman, dau, 10 years, born Woolstone, Berkshire
Sarah Whiteman, dau, 5 years, born Knighton, Berkshire
I suspect if this is George's family, he was probably at sea as he's listed as a mariner on William's baptism from 1858. There's no sign of George and Jane's marriage in either Middlesex or Surrey, so as Send isn't that far from the Berkshire border, it may have been there. You'd need a copy of one of their children's birth certificates from after 1837 to confirm her maiden name. The Send parish registers are available to view on ancestry.
It's worth bearing in mind that there is another George and Jane Whiteman in London in the St Pancras area, but they remain in London so different couple.
Hope this helps.