In work I have the full Creative Suite package and they pay a monthly subscription
I was told by someone that I could use the software at home in the evening or weekends, as long as the work PC is not signed in at the same time. Is this true?
If so, can it be used across platforms? e.g. in Work i use Windows, but at home I have an apple machine.
A Creative Cloud subscription allows for use on either or both platforms. You can install on as many machines as you like. Of all those machines you can only have two signed in for use. Of those two machines you can only be using the subscription on one at a time.
A Creative Suite license is only valid for one platform or the other, not both.