Yes, or at least it should be. If you'll ever encounter a sentence where it won't work both ways, you can report it.
Although, to be clear, there may be sentences which will make it clear if it's singular or plural, for example "You all have coffee" - here, because of the "all" part it's obvious that it's about a group of people so it could only be "Wszyscy macie kawę".
There's a huge difference, actually. "Twój" is something you'll say to one single person while "wasz" to a group of people.
Now, theoretically, the word "Wasz" could also be used as a polite form when talking to one person, but practically it's not really used like this anymore. You would have to speak to some royal family member to address one person with "Wasz" and you'd only see this in old literature, usually you'll just use "Pan" or "Pani" (Sir/Madam) as a polite form.