* Understanding the Units: Teaspoons (tsp) measure volume, usually for dry ingredients. Fluid ounces (fl oz) measure volume, usually for liquids.

* Conversion: While it's possible to convert between teaspoons and fluid ounces, it's not a direct one-to-one comparison. They are different units of measurement.

Conclusion: You can't directly say which is greater because they measure different things. 4 tsp of baking soda is a volume of a dry ingredient, and 1 fl oz of vanilla is a volume of a liquid.