Today, Bonner, who earlier pleaded guilty, appeared in the dock at the High Court in Christchurch wearing a denim jacket and sporting greying facial hair.
Justice Graham Lang told him it was a crime of extreme violence against a "very dear friend'' and he must spend at least 13 years in jail.
Ms Morris' bashed, naked body was found in the back of an abandoned car near Christchurch International Airport on January 6.
The pair had been in a sexual relationship, but that ended in 1994 or 1995, the court heard.
According to the police summary of facts, Bonner contacted Ms Morris on New Year's Eve and they arranged to meet for dinner at his house in the quiet Coniston Ave, Ilam on January 3.
She drove her blue Honda Civic to Bonner's house about 6.20pm after finishing work.
He had set up the sunroom for her to stay the night so she could enjoy a drink.
They ate dinner, drank bottles of wine she had brought and smoked cannabis.
After dinner, they watched a Dire Straits DVD and when that finished Bonner put on a Corrs DVD for Ms Morris to watch while he washed the dishes in the kitchen.
Ms Morris, who worked and socialised at Phoenix Bar and Cafe, was seated in a La-Z-Boy chair when Bonner came back into the room and attacked her from behind.
She received skull and eye socket fractures, a broken nose, broken tooth, extensive facial bruising and two lacerations to the back of her head caused by "a very forceful collision with a rounded-edged item,'' Crown prosecutor Kathy Bell told the court.
He strangled Ms Morris with her own leggings, which was the ultimate cause of death, although Ms Bell said the head injuries were life-threatening in their own right.
Bonner then dragged his friend's body through the lounge, out the back door and into her car.
He dumped the car at Greys Rd, near the airport, with the victim semi-naked and face-up. The vehicle and body were found by a passing jogger three days later.
The next day he handed himself in to Papanui police Station "after reading about the matter in the newspaper'', Ms Bell said.
He told them he couldn't remember much but "something heinous had happened''.
"The last position of the victim as recalled by the accused was of her sitting in the La-Z-Boy chair watching The Corrs and him doing the dishes,'' the Crown says.
"The next recollection of the accused was waking up in the morning and the lounge looking like a `bombsite' and that there was blood on the floor.
"The blood in the area by the La-Z-Boy ... was described by the accused as if `someone had spilt a big, really big glass of wine on the floor'.''
Before Bonner was sentenced today, Ms Morris' sister Nicola Morris read out her victim impact statement to the court, and told him: "I hope I never have a `greatest friend' like him.''
The court heard Ms Morris' son Bradley, 17, had known Bonner all his life, and had even been a ring bearer at his wedding as a 10 or 11-year-old.
When he heard his mum had been murdered, he thought that Bonner should know. He wanted to contact him, but didn't have a number, so asked police if they could put him in touch.
They told him that Bonner had admitted to the slaying, which stunned the teenager.
"I felt gutted,'' he said.
"I just feel really angry towards him. I cannot stop thinking about it.''
Justice Lang was convinced that Bonner's alcohol consumption "triggered the outbreak of extreme violence'' but accepted that the reason behind it remained a mystery.
Defence counsel Elizabeth Bulger added her client still has no recollection of events, which he accepts has distressed family members.
