I can't think of many places who store the compost indoors, i always seem to get mine from outdoors with exception of seedling composts and i had some from a growshop once.
Actually come to think about it the ones that i had indoors had pests in them, but who knows where they were stored before making it to the shops.
Never tried homebase compost so can't comment on that buddy, but if it did well in the which trials then i'd give it a go