I almost reinvented the wheel creating a new lib just to have the option to broaden the search above the 60 places limit, as I didn't know of this property.
A Google search led me to https://github.com/joshtronic/php-googleplaces/issues/5 and thankfuly I didn't need to implement a whole new thing. So I thought this property should be stated in the README.
Sort of thinking there needs to be a "walk" method. Something like $places->walk('method') so you can be all like while (...) { ... } and easily spin through. Also considering a "next" method to help grab page 2 so you're now passing around variables (that's still allowed to, I guess)