We will soon be flying into Jordan (from Canada). During our 2 weeks there, we will cross into the West Bank (Palestine/Israel). We will then go back into Jordan for our return flight. Should we buy the 2-entry visa for 60JOD as per wiki travel? Is the land crossing count the same as the air entry?
It may depend on which crossing you will use. If you go by the Allenby bridge, and return by the Allenby bridge within the visa validity, you don't need a multiple entry visa. They also do not make any stamp on your passport on the Jordanian side (and you can ask for no stamp on the Israeli side) at this border crossing.
From a much older version of the same Wikitravel page:
If you leave Jordan at the Allenby/King Hussein bridge crossing with Israel, then return while the visa is still valid so that you do not need to buy a new one. This is because West Bank is recognized by Jordan as a part of Jordan.
I did this in 2011, although looking at my passport it does appear that I paid 20 JD for an arrival visa, so I'm slightly puzzled as to whether I bought a multiple entry as that was the cost at the time per Wikitravel.
Since I assume you will be purchasing an arrival visa, you can probably just ask the immigration official to confirm whether leaving and returing via Allenby is multiple entries.