In the 1861 census John L.M.C. is with his grandparents in Ramsey, at 2 Washington? Terrace (terrible writing), one of three entries between Maughold Street entries.
Household Members:
Robert O Christian 65 Widr Engineer retired, b.Douglas
Jane S Crellin (Ancestry has "Cullen"), 28 Daur Master Mariner's wife, b.France British Subject
Jane T C Crellin 6 Mo grandaur b. IoM Ramsey
John L M Christian 7 grandson b.IoM Ballaugh
Elizabeth Quirk 53 unm serv b.Bride
Ann Jane Kirmeen 15 nurse maid b.Maughold

It is interesting that Robert O Christian was recorded as b.IoM when the 1881 census has his son Thomas Phillip Christian as b.England.
Probably ROBT CHRISTIAN Christening: 06 JAN 1796 Saint Mathews, Douglas, Isle Of Man, Father: JNO CHRISTIAN, Mother: CATH OATES, although there were many Robert Christians.
Robert Oates Christian? (The "Robt Oates Christian (dec), Gentleman" in 1877.)

There is a will for Robert Oates Christian which you should see:
CHRISTIAN, Robert Oates 1868 Ram A 8 [LDS film no.] 0106270

[There was also a THOMAS PHILIP CHRISTIAN of around the same age as your TPC, which could be confusing in later records: IGI Christening: 21 SEP 1831 Saint Mathews, Douglas, Isle Of Man, Father: PHILIP CHRISTIAN, Mother: ISABELLA KELLY.]

Your Thomas Phillip C. is in the 1851 census with Julia, in Ballaugh. Glen Tavern was given as the address of the entry above their one.
Christian Miller Hd W 71 School Mistress b.Town Ramsey
Thomas P Christian son-in-law Marr 35 Engineer, b.London
Julia L Christian Daur Marr 33 School Mistress b. IOM Castletown

The "Miller" could be Mellor - the "e" or "o" is a splodge, and the dot of the "i" is hidden by a downstroke from the entry above.

Sue