There is no problem to travel while in the process! They even issue a new visitor visa with your OWP!The OWP is not a travel document if your wife is here on a visitor visa she can go back HOME using the passport that she has but she cannot come back...
Its better you wait for the PR before making any travel plans.
Please note: For visitor visa you can legally stay in Canada only for 6 months and then you need to go back and wait for another six month then only you can return by that time your wife will get the PR... So even though you have a valid visitor visa and OWP you cant travel .. you can travel but you cant re enter.
In CIC page says that you can travel while in the process, but they can't do anything if you are refused to re-enter in the border.