Thanks to a mention of new content at the Joseph Smith Papers Project (h/t BCC) I went and took a look at the website. The JSPP home page mentioned new biographical information, so I looked at John Tanner's entry and saw a reference I hadn't noticed before about his ordination as a priest. Here is the source material, a newspaper account of Orson Pratt's early missions, referencing his journal entry for February 2, 1833.
John Tanner would have been ordained during the four days Orson Pratt and William Snow were in Bolton.
|“History of Orson Pratt,” Deseret News, 9 June 1858, 65.|
Here are Orson Pratt's travels from November 8, 1832, to February 17, 1833. Bolton shows up at (G) when he spent ten days there in late December 1832, held ten meetings, baptized ten people and (L) when he returned to Bolton at the beginning of February.
Here is a picture of Orson Pratt in his later years. He was the winner of Keepapitchinin's famous Best Beards Contest.