"Capital of Arab Culture" is really a bit pompous, to say the least. I chalked it up to some british marketing company's desire to play to the client, but personally I doubt even the Qataris believe Doha is the capital of arab culture. At least none of the ones I know do. They all laughed at the ludicrous nature of the assertion.

It would be far better to say, "Doha: Capital of Qatari Culture" and enjoy that for what it is.