Speaking at an Economic Club of NY lunch in late November, Stephenson said that if tax reform passed they would spend "at least" $1 billion and create an estimated 7,000 jobs.
Outside the White House, Republican lawmakers clapped and cheered as Trump highlighted AT&T's planned bonus payments.
Randall Stephenson, AT&T chairman and CEO said Congress, working closely with the President, took a monumental step to bring taxes paid by US businesses in line with the rest of the industrialized world.
The bonus award is expected to cost the firm about $230m and go to non-manager, unionised employees.
For its part, Comcast said it would also dole out "special" $1,000 holiday bonuses to more than 100,000 "frontline and non-executive" employees.
Shortly after the company announcements, the office of Senate Minority Leader Chuck Schumer said in a statement that the bonuses and higher minimum wages were "the exception, not the rule, when it comes to the biggest corporations spending their windfall".
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The firm had previously said it would invest $1bn more if tax reform was approved.
Wells Fargo said that it will raise its minimum wage for American employees to $15 an hour and increase its philanthropic giving by 40 percent in 2018 to $400 million.
"We want to invest in our most important asset-our people", said Greg Carmichael, president and CEO of Fifth Third.
Wells Fargo announced a similar measure Wednesday, saying it would pay more than 13,500 employees a bonue and raise the minimum wage for its workers to $15 after the Republican tax plan is passed.
Aerospace company Boeing announced that, as a result of tax reform legislation passing, it will commit $300 million to "employee-related and charitable investment". AT&T's stock rallied 1.3% in afternoon trade.
Other companies joined AT&T's announcement, providing the president with ammunition to support his claims, which are contested.
"On behalf of all of our stakeholders, we applaud and thank Congress and the administration for their leadership in seizing this opportunity to unleash economic energy in the United States", Boeing CEO Dennis Muilenburg said in a press release.
"With these investments, we expect to add thousands of new direct and indirect jobs", Comcast's chairman and CEO Brian Roberts said in the company's statement.