The short answer is yes, you should be able to get a copy of the council packet. Council packets are routinely handed out to reporters – just ask any of the big cities such as Fort Worth.
The long answer is that these documents are subject to the open records act like any other document. Therefore, if they are providing council members with copies of legal opinions or details of real estate transactions, they may be able to withhold those items. A request for a zoning change, however, would not fall under the real estate transaction – the types of real estate transactions exempted under the open records act are generally the sale or purchase of real estate. A request for a zoning change, and specifications of that request, would be public.
If the city is refusing to give you a copy of the council packet, make a formal written request for the documents. They will probably seek an attorney general's opinion. You may have to make requests every week until you get them accustomed to releasing these details to you. If you don't want them to charge you for copies, ask for access to read the packet. You would only have to pay for the pages you actually want.