Hi Anna
If you take a look at this itinerary of theirs
http://www.africaguide.com/travel/package/66.htm
next to Company Name you will see
"View Company Feedback"
click the link for a pop up window displaying all the feedback that we at the Africa Guide have received directly from people who have been on safari with Wonders of Creations following enquiries made in our Travel Center.
I am sure that this feedback will give you comfort that they are an established and reliable company. They are fully registered and licenced operators based in Tanzania.
If you want any more info or require clarification please feel free to contact us - by clicking the Send an Email link at the bottom of this message.