\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.13}
\usepackage[siunitx,european]{circuitikz}
\begin{document}
\begin{figure}
\centering
\begin{tikzpicture}[remember picture,trim axis left]
\begin{axis}[%
compat=newest,
width=0.95\linewidth,
height=5cm,
scale=.85,
scale only axis,
separate axis lines,
grid=both,
every outer x axis line/.append style={black},
every x tick label/.append style={font=\color{black}\footnotesize},
xmode=log,
xmin=1e-06,
xmax=1e5,
xlabel={Zeit in $\SI{}{\second}$},
ymin=0,
ymax=1,
yticklabels={,,},
axis background/.style={fill=white},
scaled ticks=false,
y tick label style={/pgf/number format/.cd,use comma,fixed,precision=3},
ylabel near ticks,
xlabel near ticks,
]
\end{axis}
\draw[fill=white,rounded corners=0.1cm,text width=4cm] (0,3) rectangle (2.75,3.7) node[align=center,pos=.5,font=\scriptsize] (effekt1) {Effekt1};
\draw[fill=white,rounded corners=0.1cm,text width=4.5cm] (2.4,2) rectangle (6.8,2.7) node[align=center,pos=.5,font=\scriptsize] (effekt2) {Effekt2};
\draw[fill=white,rounded corners=0.1cm,text width=4cm] (5,1) rectangle (9.5,1.7) node[align=center,pos=.5,font=\scriptsize] (effekt3) {Effekt3};
\draw[fill=white,rounded corners=0.1cm,text width=3.5cm] (7,3) rectangle (9.8,3.7) node[align=center,pos=.5,font=\scriptsize] (effekt4) {Effekt4};
\end{tikzpicture}
Siehe 17.13 Referencing Nodes Outside the Current Picture im pgfmanual. Wobei ich dann die Bilder nicht gerade in zwei verschiedene figure-Umgebungen tun würde. Wenn sie auf verschiedenen Seiten landen, kann man schlecht eine Verbindungslinie malen.