This situation is close to 'bland.' Actually, '살다' has many meanings. You can basically understand it as 'to live.' In this case, for example, 맛이 살다, 개성이 살다 , 색이 살다, 멋이 살다. 살다 means something fully reaches to or show its unique quality that sth has. So, I guess the speaker was cooking. If the situation was '맛이 안 살아', the speaker would put some ingredients or change them. I hope that my answer will be helpful to you.

i know the first one means delicious...second i am not sure..hhehe