I am planning a trip to experience LATAM and Qantas business class next year and the connecting time at AKL is 1:35. I do not plan to check a luggage. Is this enough transfer time?
LA800: SYD(11:00) - AKL (16:25)
QF158: AKL (18:00) - MEL (20:15)

Separate tickets or both flights on 1 PNR/ticket?

You are relying on the LA being on time.
https://flightaware.com/live/flight/LAN800

It is separate tickets. According to the flightaware sometimes the flight gets cancelled??

If LA801 is (very?) late from SCL to AKL, they cancel the AKL-SYD-AKL segments. Better now with a new aircraft. Cancellations more common with the old B747. If LA800 is cancelled they put you on another airline SYD-AKL

And for this reason, I have yet to fly LA800 despite trying.

Thanks for your input. really appreciate it.

On separate tickets this is risky, even with no checked baggage. You could easily have 20 minute walk between arrival and departure gates, then add time for security, to check-in (if needed), and anything more than a short delay on the first flight will lead to missing the second flight.

Hey,
We are olanning following flights
PER-SYD 23:55-6:10
SYD-AKL 9:55-15:00
AKL-PPT 16:15 ->

Question is if 1h 15min is long enough connection in AKL? Ali flights are on same ticket but NeXT flight to PPT if missed would leave next day.

We were thinking also
PER-MEL 23:55-5:20
MEL-AKL 7:45->

But with MEL is 2h25min transfer enough time to visit in QF F lounge?

AKL PPT is the QF codeshare TN operated
IF QF are selling as 1 ticket they consider it OK. QF's risk and not yours.
At AKL you would remain international airside. Just a security check.
At SYD you would have to do the T3 T1 bus shuffle.
Airport info SYDNEY (SYD) - amenities, transfers, transport Click to open the wiki

For option 2 MEL domestic & international are a 5 minute walk
You would get time for breakfast in the QF F lounge.
Option 2 would be my preference. Avoiding SYD T3 T1 shuffle is worth spending a little extra for. And more time for the AKL transit

Air NZ have a non stop PER AKL flights and AKL PPT flights

Route maps--->Great Circle Mapper

Agree with Mwenenzi, the MEL transit is the preferred option. So much easier than connecting in SYD. You will lose at least 20 minutes in SYD just going between terminals, so the lounge time isn't as big a difference as it appears. And yes you should have time to get to the F lounge in MEL.

Well, QF might be responsible for rebooking, but I wouldn't say the passenger has no risk. There is a cost to missing your flight especially when there is only 1 per day.