Amid increasing congressional scrutiny over their spectrum and reselling deal, Comcast and Verizon Wireless are now cross-promoting each other's products in San Francisco.

Verizon Wireless, which is jointly owned by Verizon and Vodafone, and Comcast kicked off their marketing and reselling arrangement last month in Seattle and Portland.

The partnership, which was first formed when Comcast, Bright House Networks and Time Warner Cable sold their wireless spectrum in December to Verizon Wireless for $3.6 billion, will allow each of the service providers to bundle and sell the others' services. The bundle includes Comcast's Xfinity video, data and landline offerings with Verizon's wireless service.

Additionally, new customers who sign up for both a qualifying Xfinity offering and a Verizon Wireless smartphone or tablet plan will be eligible to receive a Visa prepaid card valued up to $300.

In the agreement, each company bills its own customers for their respective services.

"Through our agreement with Verizon Wireless, we're delivering even more value for consumers by providing an entertainment and communications solution that fits their lifestyle both in and outside the home," said Steve White, president of Comcast's West Division.

Comcast has said it would roll out the joint marketing effort in other cities this year, but those will most likely take place in areas where it doesn't face video competition from Verizon's FiOS service.

During its fourth-quarter earnings call last week, Time Warner Cable President and COO Rob Marcus said the company planned on launching its reselling agreement with Verizon Wireless in the first half of this year in several cities. Marcus said he expects the packages to be similar to those that Comcast and Verizon Wireless are offering recently.

Bright House Networks, which competes against Verizon in Florida, hasn't said when it will start offering Verizon Wireless' service.

In late December, Cox Communications announced that it was selling its 20 MHz Advanced Wireless Services (AWS) licenses to Verizon Wireless for $315 million.

Opposition to the marketing deal and the sell of the wireless spectrum is starting to mount. Yesterday, Sen. Herb Kohl, a Wisconsin Democrat and chairman of the Senate Antitrust Subcommittee, said he would conduct a hearing on the marketing agreement and on the spectrum deals.

The Federal Communications Commission and the Justice Department are both scrutinizing the deals in order to see if they could lead to less competition and higher prices in the market. Various consumer groups have also raised their concerns over the deals.