It depends on how much you plan to grow before starting another worker/settler.
If you're staying at size 1 for now (i.e. starting another worker/settler immediately) I would expect the gold to be better, since you'll have the rice up by the time you want to start growing anyway.
If you're growing to size 2, it turns out in this case that improving gold before rice only makes the growth one turn slower. Whether it's worth it or not depends on how high you want to prioritize commerce.
If you're planning to grow all the way to size 3 or higher the general rule of focusing on food first will guide you true.
If you're staying at size 1 for now (i.e. starting another worker/settler immediately) I would expect the gold to be better, since you'll have the rice up by the time you want to start growing anyway.
If you're growing to size 2, it turns out in this case that improving gold before rice only makes the growth one turn slower. Whether it's worth it or not depends on how high you want to prioritize commerce.
If you're planning to grow all the way to size 3 or higher the general rule of focusing on food first will guide you true.