I'd allow 4 hours assuming a break in driving, the road between yatagan and milas can be tricky with trucks and some single lane carriageway / road works. Traffic in Bodrum itself usually very congested. Agree with comment that Fethiye is simply more stunning, and cheaper, that said the best parts of Bodrum are elsewhere on the peninsular, eg Gumuslik, and some of the other "villages,", together with the bits in between, somewhat similar to the kaya valley, with more Greek style old houses than around fethiye. Certainly worth exploring, enjoy.