For the avoidance of doubt, my position is not intended to make any judgement on morality of the Bomber Command campaign - for the record, I believe it was morally justifiable but do not intend to drag the thread off with a discourse on why so. I would have preferred the memorial to have been constructed at public expense, and clearly the government could have paid for both the BC memorial and the restoration of the 11 Gp bunker. But politics doesn't work like that (again, to avoid thread drift, I'm going to leave that standing as an assertion).
If a choice has to be made, for me the bunker wins. Yes, the Nazis perceived the BofB as a draw, but even if we accept that view, it was damned important not to lose! The record is replete with great battlefield victories of arguable, little or no historical significance; the reason why Trafalgar and Waterloo are (rightly) held up as victories worth commemorating is their profound strategic legacy, establishing as they did a century-long British pre-eminence. For me, the BofB joins this elite pairing because of its profound strategic significance, regardless of whether it can be counted as a tactical victory. As others have pointed out, the bomber campaign, OVERLORD and the NW Europe campaign were all dependent upon Britain avoiding defeat in those critical early stages of the war, and the BofB marked the first significant failure of the thereto-unstoppable Nazi war machine. We still remember Drake's defence against the Spanish Armada for similar reasons.
As a final point, beyond its preservation as a memorial to the BofB, the 11 Gp bunker serves as a superb testament to the ingenuity of our scientists (radar), to the value of bold and innovative military thought (Dowding and Park), and to the social revolution-precipitating role of women in war (WAAF plotters). In other words, it shows how an educated, liberal, enlightened society has significant strengths which can be drawn upon in adversity, despite the misgivings of many. As a relic or monument to visit to remember and think upon military matters, I consider it rivalled in the UK only by HMS Victory.