Not sure of any out of the box WiFi enabled landscape lighting transformers but your question got me to thinking.
Why not use a Sonoff 4CH coupled with something like this
That would give you 4 controllable channels and if you flash the Sonoff with Tasmota firmware you could easily add any additional sensors that you want.
I only briefly looked so that 120VAC-to-12VAC unit may not be the best but I’m sure there are plenty of other options available. I might just have to add this to my list of projects. A couple of my transformers are outside so I would need to get a water tight enclosure to house these units but I think you still might be at the same cost or lower and with more functionality.