Under the  Wales Bill, currently going through Parliament, Welsh ministers could vary income tax by up to 10p in the pound, subject to a referendum.
Mr Jones said that "on balance" a referendum would still be needed.
But opposition parties suggested extra powers being offered to other parts of the UK could make a poll unnecessary.
Assembly party leaders were giving evidence to the Commons Political and Constitutional Reform Committee, meeting in Cardiff Bay, which is holding an inquiry into the future of devolution.
Mr Jones said: "Is there a need to have a referendum specifically on income tax devolution in Wales?
"I think on balance I would say referendums still need to be held but given the pace of change elsewhere in Scotland...I am very wary of any suggestion, leaving aside what I've said on income tax, that every change in Wales needs to be approved by a referendum."
Plaid Cymru leader Leanne Wood said AMs should decide on income tax, if English regions were to gain tax powers without referendums.
"Given that there will be some tax powers offered, in all likelihood, to some of the English regions now, without the need for a referendum, we would argue that that changes the picture for Wales," she said.
"Tax powers should be able to be triggered by the representatives of the people of Wales via this institution."
Welsh Liberal Democrat leader Kirsty Williams also questioned the need for a poll, if parties put the issue of devolving income tax powers to Wales in their general election manifestos.
"I really wonder whether that's necessary, especially if all political parties had it in their manifestos in May and people were elected on the basis of that," she said.
Welsh Conservative leader Andrew RT Davies said he was "open-minded" about the need for a referendum, but noted that a specific question on income tax was included in Scotland's 1997 referendum which has not been put to voters in Wales.

The country's current T20 Challenge series consists of six teams but the new T20 Global League would be made up of eight city-based franchises.
"We are confident the window we have chosen will make it possible to attract top-class players," said CSA chief executive Haroon Lorgat.
CSA informed the International Cricket Council of its plans this week.
A worldwide tender has been put out by CSA and the deadline for expressions of interest is Friday, 3 March.
"Our vision is to drive the creation of a new T20 destination league  that would energise the sport of cricket in South Africa by creating a global platform for the best-in-class to perform and showcase their talent to a global audience," said CSA president Chris Nenzani.
"We have received a very favourable response to our plans from the ICC and member boards and look to their support."
A referendum still needs to be held before income tax powers are devolved to Wales, First Minister Carwyn Jones has told MPs.
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Cricket South Africa is planning to launch a new Twenty20 league to be played in late 2017.