Since poppy pods can vary so greatly in quality, there is no "standard" dosage in place. Not to mention that some strains are more potent than others, and so on. Depending on tolerance and other factors, it may only take a couple of pods to gain the desired effects, or it may take twenty. It is a natural product after all, so alkaloid content will vary from plant to plant.
Remember: These are very potent plants, and you should exercise great caution when partaking in poppy tea.
The general rule of thumb should always be to START SMALL. If you must insist upon putting these substances in your body, then it is far better to start small and waste a few pods, than to use too many and end up sick, or even dead.
This rule should apply whenever you aquire a new batch of pods, and not just when you drink your first cup. The potency of pods, even when aquired from commecial suppliers, can change on an almost daily basis. So never assume that the same dosage will always have the same effects.
If you cannot treat these substances with the respect that they deserve, then you should not even consider drinking poppy tea.