Australia Death Index, 1787-1985
Name: Jas Tavener
Death Place: Tatura, Victoria
Age: 66
Father's Name: Tavener Hy
Mother's Name: Cath Thoms
Registration Year: 1903
Registration Place: Victoria
Registration number: 7779
Estimated Birth Year: abt 1837

Yes I saw that 1841 census and perhaps James Tavener emigrated with his father, Henry, Perhaps this Henry Tavener Below:
Australia Death Index, 1787-1985
Name: Henry Charles Tavener
Death Place: Victoria
Age: 68
Father's Name: John
Registration Year: 1868
Registration Place: Victoria
Registration number: 8828
Estimated Birth Year: abt 1800
From The McIvor Times Friday 9 October 1868
A FATAL ACCIDENT.
On Sunday night last as an elderly man, named Henry Tavener was proceeding home from Heathcote to Costerfield with his son in a spring cart, when ascending the rise on the east side of the creek the cart came in contact with a stump and capsized, when the poor old man was literally crushed, the severity of his injuries will be learned from the medical evidence given at a magisterial inquiry, which we subjoin. The deceased was familiarly known as "old daddy" by a large number of old residents here. He was sixty-eight years of age:
Charles Robinson sworn, said?"I am a legally qualified medical practitioner, resid- ing at Heathcote; On Sunday night last between twelve and one o'clock I was called up to attend the deceased, Henry Charles Tavener, who was brought to the Hospital at that time; on examination I found a fracture of the bones of the left leg, about four inches above the ancle, fracture of the left thigh bone, a few inches above the knee joint, fracture of several of the ribs of the left side, and a comminuted fracture of the left clavicle. He was perfectly sensible, but in great pain, his extremities were cold; on Tuesday morning he became comatose, was unable to arti- culate. He continued in that state till between 4 and 5 o'clock this morning, when he died. I have this afternoon (Wednesday) made a post mortem examination on his body. The nine upper ribs of the left side were fractured, and the first rib of the right side. A considerable quantity of blood was effused in the left cavity of the chest, the left lung was red and conjested, I believe it to have been contused from external violence. The death was caused by shock to the system, produced by the in- juries I have described. He was sixty-eight years of age. The injuries were the result of great external violence."

Of course it could be a different Henry but not many spell Tavener without the R.

This interesting as I found an article re Henry C Taverner wife Caterine and child (only 1 though) arriving on the barque Pheobe 1846 5 may Adelaide. James would have been 9 and maybe Henry (jr) remained in England as he would have been 19 by then. Still not sure but your info is helpful. I also spoke to D Tavener of Tatura whom told me that the family story is that James had jumped ship at Portland and travelled nth. This throws the Pheobe idea into confussion.

according to cemetery records this particular Henry is buried at Heathcote Cemetery although not on this list, (which is incomplete) it might pay to email Carol and see if there is any other info. Perhaps a next of kin. even a religion can help.
Australia Cemetery Index, 1808-2007
Name: Henry Tavener
Death Age: 68
Birth Date: abt 1800
Death Date: 1868
Burial Date: 8 Oct 1868
Cemetery: Heathcote
Cemetery Location: Heathcote, Victoria

Thanks