Diane,
I"ll assume your message was meant for me. Halberstroh does not give the years of service for the listed clergy.
However, I did a search for "H.F. Bernhart" [exact phrase] at
http://www.fultonhistory.com/and came up with a few hits about him. The church seems to have had several incarnations and names. A May 8, 1891, article in The Sun says he is pastor of the newly formed Free German Evangelical Protestant Church that seceded (interesting to read why they split!) from the Hopkins Street Presbyterian Church. The new church had just purchased land on Throop near Myrtle Ave. So for your people, 1889-1890, you would likely want the Hopkins Street Church. Another article from Oct. 1887 indicates H.F. Bernart was a candidate for pastor at the German Evangelical Mission Church of Hopkins street, after the death of its pastor, John Meury.
I do not have Halberstroh with me at this time to check where any of those records might be; email me directly and I'll answer asap.
Pat
pat4gen@hotmail.com