Bubble anemones are the easier anemone to keep and I would even go on to say that they aren't that difficult to keep at all. They do however need proper conditions in order to thrive. What is your lighting like, and give some numbers for your parameters. If it is not showing any tentacles expansion after one month than their is something very wrong with the anemone. It should have been expanded after a couple of days, and nothing longer than a week. Perhaps something is harassing it? What are the tankmates, and clownfish species hosting if any?