In England a book of this sort might be titled "Philosophical Theology"; this would prove a more apt title. This is easy to see in discussions of omnipotence and divine command theories and even more so in those about prayer, human worth, and the atonement. Some of the discussants commend appeals to theology, and the theology in question is broadly Western and theistic and, in some cases, specifically Christian. Hence, there's little philosophy of religion in this book and more philosophy of God (even the God of Abraham, Isaac and Jacob). This is just an observation.
I have always said it makes no sense to call the field "philosophy of religion" if you aren't going to discuss religion in an anthropological or sociological sense. A philosophy of religion should range widely among different religions, just as anthropology of religions; it should range far more widely than the topics usually discussed, which would be better called 'natural theology' or, at the very least, as Clark suggests, 'philosophical theology'. When it is used for the latter, it is a weasel phrase, a way of saying you do theological metaphysics without having to come out and say it. The label would be best reserved for those philosophical explorations that parallel anthropology of religion, or sociology of religion, or psychology of religion.
Indeed, this is exactly why the label began to be used in the first place; all the earliest uses of it are along these lines, although in practice Christianity was often the primary religion in view. So people would ask: "What are the origins of religious life? How did religious consciousness evolve? What are the relations between religious life and moral life? What social functions are fulfilled by taboos and priestly laws? What are the key differences between different religions and what are their philosophical significance? What is the relation between religion and teleology? What counts as a distinctively religious experience? Is there a particular sort of religious knowledge? What is the best way to understand acts of worship?" And so forth. But in the twentieth century there was a revival of interest in the sort of topics that used to be called natural theology; without, however, there being any place to discuss them respectably. So people began sneaking it into the philosophy of religion courses, whence it ended up dominating it entirely, actually pushing out most of the philosophical work that had previously been done in the field. That the topics came back to be seriously considered is great; that they only did so by largely pushing out legitimate work is not.