Virgin �5 sim only Can you use BBM/internet via house internet wi fi?

I just bought your �5 unbeatable sim (virgin) for an old version of the blackberry bold. I thought i only got unlimited texts and 100 minutes, but when I clicked on BBM it allowed me to add a name etc. Is this because i can Access internet and bbm through my wi-fi in my house? or am I paying for this? Thanks!