Can I power my house from my vehicle with V2G or V2L?

Yes you can, more or less, to some extent, but it's a little complicated. We have an article that explains the terminology, but V2G or V2H versus V2L are really about capacity.

Right now the Nissan Leaf, Outlander, EclipseCross(?) or iMiev (CHAdeMO plug equipped) vehicles can charge or discharge at a full 7kW or 30 amps. For reference, a standard house supply from the street is normally 15kW or 63 amps (but it may surge to 100 amps for 100 seconds before the main service will blow) The Wallbox Quasar is approved for grid connection but it will not function without the mains supply available. It's not a grid forming device that can operate as an islanded system. Interestingly it seems Tesla have now decided they'll enable bi-directional on their cars... from 2025?

However, I don't know if this arrangement would be something that plays well with an off grid system. AC coupled integration may be a problem to solve yet because the grid is able to soak up almost infinite amounts of energy, whereas an off grid system has a limit. When the battery is charged you have to turn the inputs off, which means having closed loop control.

V2L is a more modest supply from your car to just about anything with a plug on it. It's governed by the inverter that the EV comes with (if there is one on board) so while some might be a few hundred watts, others might be 2kW or 3.6kW perhaps, (8 to 15amps). Running appliances and even a kettle isn't out of the question provided they don't have large surge loads. 

A decent V2L output from your EV can be though of as a camping generator like a Honda 2.2i and it's legal to use one in the same fashion. You can have a generator inlet switch wired to your house and devote some essential circuits to it. But it wouldn't be capable of running your refrigerative air con, and might struggle with a rainwater pressure pump for instance.  Also be aware you could strike issues with your home's MEN (Multiple Earthed Neutral), which may trip the RCD on your vehicle.

V2L could also be used as a generator input for an off grid or hybrid system, should you want to go to the big smoke, charge up and then bring a bucket full of energy home to siphon off into the house. With a decent capacity off grid system and some smarts to control it you could also charge an EV with an off grid system using conventional charging equipment... but not simultaneously.

There are already stories of people running houses for days on end using a V2L adaptors in cyclone battered USA and New Zealand; so that's certainly a very useful option people will become increasingly interested in.
 
We have seen some alibaba special inverter devices from China that use a CHAdeMO plug to run a decent sized inverter, which you could use as an input to your off grid house... but I don't expect these are an Australian compliant device and I don't know what other V2L is available for the Leaf.

Check the specs on the EV you plan to buy. A KIA EV6 is the best I'm aware of at the time of writing; they run 3.6kW V2L inverter so that's a pretty healthy 15 amp supply.