It is always very tempting to think that the speaker of a poem is the same as the poet herself, especially when the poet chooses to use first person. Dickinson makes this assumption even more tempting because she tends to stick to topics that are known to be of interest or highly relevant to her life. However, we should never assume that it's the poet herself speaking, unless the poem tells us that it is, or if the poem was published with some sort of introduction that tells us that it's autobiographical. In fact, Dickinson herself has told others that her first person narrators are a "Representative of the Verse" and a "supposed person," not actually herself. So if it isn't the poet, who is it? We don't know for sure, but we can get some hints about the character and why she's (one thing we'll assume is that our speaker is a she) telling us these things from the poem.
The speaker seems to want us to believe that she's a bit of a lowbrow with the references to "tankards" and what appears to be beer. She's also familiar with the idea of being booted from a tavern and the overall concept of drunken debauchery. She can't fool us though. The influence of the poet's wealthier background comes shining through in the references to higher class (and price tag) wines. It's also hard to ignore the fact that the speaker is out flitting around in nature on a glorious summer day, seemingly without a care in the world. A lower-class citizen would probably either be stuck inside somewhere working or toiling in conditions that would hardly make her happy about being outside. It's far more likely that someone who is well-to-do would be raving about their ability to get drunk off air.
The speaker is also very pious. Only the morally upstanding and squeaky-clean living would catch the attention of Seraphim and saints alike. Of course, she's making a joke out of sin by using a real sin as the vehicle for the metaphor used to describe something quite wholesome. The angels and saints dig those kinds of jokes though, because they're tossing their hats and celebrating along with our speaker.
In the end, our speaker has a lot in common with Emily herself: pious, well-off, but most of all totally jazzed about the wondrous beauty of the natural world.