The sinusbot itself doesn't use lots of memory but reserves a fair amount. However, this doesn't count as used, so you don't need to worry about it. More details about memory usage on linux can be found here.
The actual TeamSpeak Client instances require more RAM, from which a big part is shared between multiple instances - so again: you probably don't need to worry about it.
If you TeamSpeak Server has an big/animated server banner than that will significantly increase RAM usage.