Foreign travel solely for business is fully deductible. Foreign travel expenses are fully deductible if you spent 100 percent of your time abroad on business. However, if you engaged in any non-business activity, whether sightseeing or visiting old friend, you may have to make an allocation between deductible business expenses and non-deductible personal ones.
If your spouse travels with you, you usually can not claim any deduction for your spouse's expenses. For the travel expenses of a spouse to be deductible, the spouse must also be an employee of the business (I would take this to mean that in regard to your rental activity your spouse must perform or assist you in what you do). In addition, the spouse's travel must be for a bona fide business purpose and the expenses must be otherwise deductible by the spouse.
Expenses must be ordinary, necessary and reasonable.
so the question is - is the travel for both necessary? you'll have to make this decision. I come across cases where the spouse's travel expense was disallowed when she was just along for the trip - in other words, there was no business purpose for both spouses
