Your kiddo should be getting somewhere around 7.5-12 oz per day. See this good feeding calculator for more info:
Dogs feeding chart - Nature's Logic
So, you're not too far off here. Each dog is an individual and some people may need to feed a little less, some a little more. You'd decrease the amount once your pup reaches >80% of his adult weight.
As far as 2x day feedings, I think I went down to that around 6-8 mths or so.