Bloom.fm, a U.K.-based streaming music service, has reportedly been blocked from using iAd by Apple. A spokesman for Bloom told CNET Apple must view the much smaller service as a threat. “We were surprised at Apple’s decision to ban us from their iAd network as their iTunes Radio service isn’t even available in the U.K.,” the spokesman said. “Bloom.fm gives you 22 million tracks for £1 a month — the price of a single…