This is a common question tossed around by everyone at some point or another. At first glance the simple and obvious answer is sure, of course. It’s the same concept after all. Steep leaves (as opposed to grounds) and then strain them out with the plunger.
Upon deeper consideration however you’ll find that steeping tea leaves in a french press isn’t the ideal way to brew loose leaf tea. Sure it works just fine but you have better options out there.
Most avid tea drinkers will tell you that they have steeped tea in a french press; it is after all good for any steeping and straining activities. What they will also tell you is that when they use a french press to make their tea they have to immediately remove all tea from the press pot right away so as to prevent the tea from getting too bitter as it happens fairly quickly.
When making coffee the plunger gets depressed all the way to the bottom but with tea you shouldn’t do this because it will squeeze the unwanted bitters from the leaves and in a related way the plunging action itself is a more delicate process in tea making. Tea leaves are shaped far differently then coffee grounds. They can clog the fine mesh a lot easier so you have to take greater care when stirring and pressing the plunger.
Long story short french press pots are great for coffee and perfectly acceptable for brewing loose leaf tea but there are better tea brewing methods. However for travelers the french press is a great option as it’s portable, easy, and versatile. I have a list of good french press travel mugs here to review but you might be best looking for a travel mug made for tea as they usually have a tea chamber than can be removed from the mug after steeping is completed.