
WabbitHuntr |

I would think so.
Sermonic Performance: " This ability is similar in all respects to bardic performance as used by a bard of the same level (including interactions with feats, spells, and prestige classes),"
Magic items are not included in the list but likely can be included with feats, spells, and prestige classes

Rub-Eta |
A Cleric is not a Bard. Even if they do share some class abilities via an archetype or any other manner.
There's also a recent FAQ about items referring to specific classes and their class abilities. The FAQ says that those items are only usable by the specifically referred class(es), not other classes with the same class ability (unless it is specifically called out to work, such as the case for Brawlers in regards to Fighter and Monk items).
EDIT: It is not a question about how the Evangelist's class ability is worded in regards to function such as a Bard's class ability with feat interactions. The Banner of the Ancient Kings are referring to a class, not only a class ability. The Evangelist does not mention anything about being a bard in regards of magical items, not even for the Sermonic Performance class ability.

Rory |
I rule it as it does.
Sermonic Performance: An evangelist gains the ability to deliver a select number of supernatural and spell-like performances through the force and power of her divinely inspired preaching and exhortation. This ability is similar in all respects to bardic performance as used by a bard of the same level (including interactions with feats, spells, and prestige classes), using Perform (oratory) as the evangelist's performance skill. However, an evangelist gains only the following types of bardic performance: countersong, fascinate, and inspire courage at 1st level; inspire greatness at 9th level; and inspire heroics at 15th level. Sermonic performance replaces the 1st-, 9th-, and 15th-level channel energy abilities. This caps the cleric's channel energy damage at 7d6 points.
In order for the performance ability to act the same "in all respects", I don't see how it can't work the same with evangelist clerics as it does with bards.