//lopp
<div class="col-xs-12 col-md-4">
    <ul class="list-unstyled">
        <li v-for="(repeat, index) in repeats">
            <span class="label label-violet">Powtórzenie @{{ index+1 }}</span>
            <input type="text" v-model="repeat.repeat" :value="repeat.repeat">
        </li>
     </ul>
</div>

//app.js
const app = new Vue({
    el: '#app',
    data: {
        message: 'Hello Vue!',
        selected: '',
        options: [
            { text: '1', value: '1' },
            { text: '2', value: '2' },
            { text: '3', value: '3' },
            { text: '4', value: '4' },
            { text: '5', value: '5' },
            { text: '6', value: '6' },
            { text: '7', value: '7' },
            { text: '8', value: '8' },
            { text: '9', value: '9' },
            { text: '10', value: '10' }
        ],
        repeats: [],
        weights: [],
        times: []
    },
    methods:{
        onSubmit:function(){
            console.log('sssssssssssssssssssssssssssssssss');
        },
        addRow:function(){
            for(i = 0; i < this.selected; i++){
                this.repeats.push({repeat:''});
                this.weights.push({weight:''});
                this.times.push({time:''});
            }
        },
        deleteRow: function(index) {
            this.repeats.splice(index, 1);
            this.weights.splice(index, 1);
            this.times.splice(index, 1);
        }
    }
});