MARION — Voters in the growing Linn-Mar Community School District will decide next month whether the school district can build two new schools. A $55 million bond question will be on the ballot Sept. 11 in the district, which includes areas of Cedar Rapids, Marion, Robins and rural Linn County. The bond would fund the construction of two new buildings for fifth- and sixth-graders. The bond, which requires 60 percent voter approval to pass, would increase the district’s property levy rate to about $18.02 per $1,000 assessed value.