I've owned the FE35mmf1.4. Great lens, sharp and nice bokeh. I have not tried the Tamron. My guess, and only a guess, is that at 35mm f2.8, both are sharp, with the 35mm perhaps sharper at the edges. But lenses are more than sharpness and bokeh. And 35mm is not good for portraits. Perhaps you should consider the Sony FE85f1.8 for portraits. It's about S$800.For portraits, how's the bokeh and sharpness at 75mm F2.8 compared to say Distagon at 35mm F1.4?
By the way, the Tamron is over-priced here at $1499 list while it is USD799 or S$1,100+7% GST i.e. $1,177.